I have the same thing happen to me but I haven't got a clue what's causing it. Pretty harmless little bug though all it affects is the naming, so I wouldn't wprry about saving.
I'm probably a bit paranoid about save corruption considering MW's known issues.
I used to get that frequently as well. I think hitting my right shift key always fixed it for me. Haven't been playing lately, so might have slipped my mind which one did it.
Hmm, I known I've tried the caps lock key and the left shift key...not sure about the right. I'll have to be sure to try that next time it happens.
Perhaps post your mod list? If other people have gotten that bug, perhaps someone will recognize a mod in common and you can at least nail down the culprit.
Edit: Have you been doing anything outside of the game before a session when this happens? Cleaned a save, merged a list, use some tool...?
Yup, here's the mod list. Figured it might be a known bug, so thought I'd try for a quick answer first.
Spoiler 001 Morrowind.esm
002 Tribunal.esm
003 Bloodmoon.esm
004 Texture Fix - Bloodmoon 1.1.esm
005 Texture Fix 1.8.esm
006 Morrowind Patch 1.6.5 Beta (BTB Edit).esm
007 Book Rotate.esm
008 Morrowind Advanced.esm
009 Hilgya the Seamstress.esm
010 abotWaterLife.esm
011 The Undead.esm
012 Ward of Akavir.esm
013 GDR_MasterFile.esm
014 Havish.esm
015 BT_Whitewolf_2_0.esm
016 constance1_0.esp
017 abotGuars.esp (Version 1.17)
018 ImprovedTeleportation2.0.esp
019 GCD v1.08 with Startscript, fixed [Galsiah].esp
020 GCD Over 60 level speedup.esp
021 GCD settings hard.esp
022 Piratelords Trade Enhancements.esp
023 TheForgottenShields - Artifacts_VN.esp
024 EcoAdjMerchantSkills (Disposition Edit).esp
025 EcoAdjCrime (Tresspass Edit).esp
026 BTB - Character.esp
027 BTB - Spells.esp
028 BTB - Alchemy.esp
029 BTB - Equipment.esp
030 BTB - Settings (Alternate).esp
031 Clean Ultimate Morrowind Anti-Mod.esp
032 Less Lore.esp (Version -01)
033 LadyD_Reduced_Commentary.esp
034 Quieter_UI_Sounds.esp
035 Sleepers-fix.esp (Version 1.1)
036 AscendedSleeperSFX.esp
037 Steel Broadsword Fix BM.esp
038 HospitalityPapers.esp
039 GnisisEggminePass.esp
040 Faction Hellos.esp
041 Book Rotate - Tribunal v5.3.esp
042 Book Rotate - Bloodmoon v5.3.esp
043 PotionSorter.esp
044 DremoraLootEnhancementMWA.esp
045 NoShieldEffect.esp
046 Improved Skilled Magicka.esp
047 belladonna.esp
048 frostmoth_repaired_v0_31.esp
049 MA_skaal_shields.ESP
050 The Imperial Legion Badge.esp
051 Service_Requirements_V1.4.3&WGI.esp
052 TheRedoran_v1_00.esp (Version 1.00)
053 BT_Whitewolf_2_0NOMaddon.esp
054 Havish - Scimitar Update + GCD (no MWE).esp
055 havish13_nom_patch.esp
056 Havish Mini Patch.esp
057 The Holiday Mod.esp
058 Clean chapelsv2.esp
059 master_index.esp
060 DXM_masterindex_journalfix.esp
061 MTC.esp
062 Haunted Tombs v1.06.esp (Version 1.06)
063 Museum of Artifacts Improved Expanded.esp
064 Better Bodies.esp
065 New Argonian Bodies - Mature.esp
066 New Khajiit Bodies - Mature.esp
067 UQFsMasterFacePack.esp
068 Westly's Master Headpack X.esp
069 Hazelwood 1.0.esp
070 Homes To Let v2pt0.esp
071 Larger Indarys 1.1.esp
072 Larger Indarys Manor.esp
073 Abu Manor v.2.esp
074 Clean Feyiin's trouble.esp
075 Blodskaal_House.esp
076 Cragonmoor v 1.1.esp
077 Clean Pegasus House BETA.ESP
078 Hilgya the Seamstress Expansion 1.esp
079 Scissors & Thimbles Merge.esp
080 Sotonhorian.ESP
081 LeFemmArmor.esp
082 adamantiumarmor.esp
083 EBQ_Artifact.esp
084 Clean Netch Adamantium Armor IIa.esp
085 sm_netchadamantium_Weapons.esp
086 Area Effect Projectiles.esp
087 farrp_WeaponCompilationMod_V2.esp
088 MoreGems.esp
089 Pearls Enhanced - Colored Pearls Add-on.ESP
090 MA_berserk_potion.ESP
091 MA_nordamulets.ESP
092 BB_Grimoires.esp
093 Books of Vvardenfell.esp
094 House of Mannequins v1.0.esp (Version 1.0)
095 House of Mannequins - Mistform fix.esp
096 Key Replacer Trib & BM.esp
097 Clean KeyNamer.esp
098 Better Clothes_v1.1_nac.esp
099 More Better Clothes.ESP
100 BetterClothesForTB.esp
101 Divine_domina_part_1.esp
102 Divine_domina_part_2.esp
103 Divine_domina_part_3_Tribunal.esp
104 Divine_domina_part_4.esp
105 Divine_domina_part_5.esp
106 Ice's BM Ice & NordicMail.esp
107 Ice_Wolf_Cuirass_Mod.esp
108 Clean Mistress Miaura's Black Domina.esp
109 MA_snowprincetomb_v3.esp
110 correctUV Ore Replacer 1.0.esp
111 Dagger of Symmachus.esp
112 sm_necro_staff.esp
113 Textured_Signs_Neutral.esp
114 moons_soulgems.esp
115 Better Skulls.ESP
116 Lantern replacer By Leeloo.esp
117 Westly_Presents_Unique_Corprus_Stalkers.esp
118 Unique Jewelry and Accessories_no ench.esp
119 LeftGloves_Addon_v2.esp
120 UFR_v3dot2.esp
121 Windows Glow.esp
122 Windows Glow - Tribunal Eng.esp
123 Windows Glow - Bloodmoon Eng.esp
124 Windows Glow - Raven Rock Eng.esp
125 LOCH_Cliffs_Of_Fjalding.esp
126 Fortified_Thirsk_1.1.esp
127 Thirsk Expanded.esp
128 Frostmoth Docks.ESP
129 Ald Redaynia Extended.esp
130 Redaynia Village.esp
131 Guarded GhostGate.esp
132 Clean Atmospheric Balmora.ESP
133 MDP - Merged.esp
134 Khuul Expanded.esp
135 MCR_Lighthouse for Khuul Expanded.esp
136 New Gnaar Mok.ESP
137 New Gnisis 1.2.ESP
138 Fields of Kummu Expanded.esp
139 Vos Expansion.ESP
140 Kogoruhn ruins 1.0.ESP
141 Cali_StarstoneOutpostPlusAddonsMerged.esp
142 Welcome to the Arena! v5.0 (normal).esp
143 Animated Morrowind 1.0.esp
144 Animated Morrowind II.esp
145 DN_1st_Person_Armor.esp
146 DN_1st_Person_bodies.esp
147 TravelingMerchants_v2.2.esp
148 Hold it - replacer.esp
149 Hold it - NOM addon.esp
150 NX9_Guards_Complete.ESP
151 Balmora Dialogue.esp
152 Ascadian Isles Dialogue.esp
153 What Thieves Guild.ESP
154 Nasty Camonna Tong.esp
155 Djangos Dialogue.ESP
156 LGNPC_NoLore_v0_83.esp (Version 0.83)
157 Lgnpc_SN.esp (Version 0.31)
158 LGNPC_GnaarMok_v1_20.esp (Version 1.20)
159 LGNPC_AldVelothi_v1_20.esp (Version 1.20)
160 Less_Generic_Tribunal.esp
161 LGNPC_MaarGan_v1_20.esp (Version 1.20)
162 LGNPC_HlaOad_v1_32.esp (Version 1.32)
163 LGNPC_Aldruhn_v1_20.esp (Version 1.20)
164 LGNPC_Aldruhn_v1_20_suppl.esp
165 LGNPC_Pelagiad_v1_30.esp (Version 1.30)
166 LGNPC_TelMora_v1_20.esp (Version 1.20)
167 LGNPC_Khuul_v2_20.esp (Version 2.20)
168 LGNPC_VivecFQ_v2_10.esp (Version 2.10)
169 LGNPC_TelUvirith_v1_20.esp (Version 1.20)
170 LGNPC_SecretMasters_v1_30.esp (Version 1.30)
171 LGNPC_IndarysManor_v1_51.esp (Version 1.51)
172 LGNPC_VivecRedoran_v1_50.esp (Version 1.50)
173 Less_Generic_Bloodmoon.esp (Version 1.2)
174 Less_Generic_Nerevarine.esp (Version 1.21)
175 LGNPC_PaxRedoran_v1_20.esp (Version 1.20)
176 LGNPC_SoulSicknessPatch_v1_00.esp (Version 1.00)
177 MTC-LGNPC Pelagiad.ESP
178 MTC-LGNPC SN.ESP
179 Blight Bounties.esp
180 The Sable Dragon 1.6.esp (Version 1.6)
181 TC_PuzzleCanol.esp
182 DN-GDRv1_NOM.esp (Version 1)
183 The Neverhalls.esp
184 sm_ForgottenHalls.esp
185 Telos Rin Graveyard.esp
186 Of Love and Ignorance.esp
187 Tales of the Bitter Coast.esp
188 Clean Tales of Seyda Neen.esp
189 Illuminated Order v1.0.esp
190 Illuminated Order v1.0 - Bloodmoon Compatibility Extras.esp
191 Clean Aln'Baldrahn.esp
192 ME_ArcaneGuard.esp
193 IoC_Clean_FullV1.0.esp
194 Quests - Darkelfguy - Merged.esp
195 Northern Winds V1.1.esp
196 Serabul.esp
197 Serabul - NOM Patch.ESP
198 Antares' Creatures - Cecaelia.esp
199 Antares' Creatures - Frost Giant.esp
200 Antares' Creatures - Treant.esp
201 Antares' Creatures - Trolls!.esp
202 Greater Undead.esp
203 DX_CreatureAdditionsV1.0.esp
204 Bloodmoon_Creatures.esp
205 Frost_atronach_solsthiem.esp
206 Dahrk Creatures I.ESP
207 sm_creatures_01.esp
208 sm_creatures_02.esp
209 Creatures.esp
210 MW_Adv_Required (BTB Edit).esp
211 Minions of House Dagoth.esp
212 Neo's Unique Creatures.esp
213 NX9_ghosts_wraiths.ESP
214 NX9_liches.esp
215 Expanded Sounds.esp
216 Bloated Caves.esp
217 Graphic Herbalism.esp
218 Graphic Herbalism Extra.esp
219 NoM 3.0.esp (Version 3.03)
220 NoM_IO Compatibility Patch.esp
221 Merged_Objects.esp
222 MO_Patch.esp
223 MO_NPCPatch.esp
224 PTE Clothing Patch.esp
225 BTB Clothing Patch.esp
226 DM_DB Armor Replacer-ExpDDBA (BTB Edit).esp
227 MTC no buff.esp
228 Immersive Chargen.esp
229 Mashed Lists.esp
Also, FPS Optimizer 1.96, MWSE 0.9.4.1, MCP 2.0 Beta (not sure which version), Exe Optimizer 1.8.
EDIT: Oh, to answer your second question, although I do game maintenance from time to time such as cleaning a save, etc, it doesn't seem to be related to that as it definitely happens when I've done nothing like that.