I was crossing near the Old Bridge recently, and found a chest under the bridge that said "dead drop orders 3" on it. I thought it was weird since I'm not even a member of the DB. When I took the gold out of it, I received 1 infamy, and the quest update. Is there a mod that caused the DB quests to be open? or is this a vanilla glitch? If anyone else is aware of this problem, please let me know. Thanks

My current load order is:

Active Mod Files:00  Oblivion.esm01  Cobl Main.esm  [Version 1.72]02  Oscuro's_Oblivion_Overhaul.esm  [Version 1.33]03  Mart's Monster Mod.esm  [Version 3.5.5b4]04  Mart's Monster Mod for OOO.esm  [Version 0.9.8b5]05  CM Partners.esm06  Toaster Says Share v3.esm07  DIM Elves Of Lineage II Retex.esm08  Tabaxi_Race_BAB_Robert.esm09  Oblivion_SI Vwalk Full.esp0A  Unofficial Oblivion Patch.esp  [Version 3.2.4]0B  UOP Vampire Aging & Face Fix.esp  [Version 1.0.0]0C  Oblivion Citadel Door Fix.esp0D  DLCShiveringIsles.esp0E  Unofficial Shivering Isles Patch.esp  [Version 1.4.0]0F  Enhanced Water v2.0 HD.esp++  Enhanced Water v2.0 HD - SI Addon.esp  [Version 0.1]10  MIS Low Wind.esp11  MIS New Sounds Optional Part.esp++  Item interchange - Extraction.esp  [Version 0.76]12  P1DseeYouSleep.esp13  TryBeforeYouBuy.esp14  Living Economy.esp15  Living Economy - Items.esp16  HotkeyCasting.esp17  sr_super_hotkeys.esp++  MaleBodyReplacerV4.esp18  BlackLuster.esp19  Eyren_AyleidWarrior.esp1A  Ice Gowns for HGEC.esp1B  RealSwords - Argonian LO-NPC.esp1C  RealSwords - Bosmer LO.esp1D  RealSwords - Breton LO.esp1E  RealSwords - Goblin.esp1F  RealSwords - Khajiit LO-NPC v1.3.esp20  RealSwords - Nord LO-NPC SI.esp21  RealSwords - Orc LO-NPC v1.0.esp22  RealSwords - Redguard LO-NPC.esp23  Elegance_HGEC.esp24  JB Catsuit Variants.esp  [Version 1.5.]25  JB Catsuit Weapons.esp  [Version 1.5.]26  Morrowind Robes and Dresses for HGEC.esp27  R18PN - Amy Armor Set.esp28  R18PN - Lingeries.esp29  R18PN - Mizugi set.esp2A  Gloria Armor.esp2B  Slof's Horses Base.esp2C  Dude Wheres My Horse.esp2D  Cobl Glue.esp  [Version 1.72]2E  Cobl Si.esp  [Version 1.63]**  OOO 1.32-Cobl.esp  [Version 1.72]++  Cobl Tweaks.esp  [Version 1.44]2F  Oscuro's_Oblivion_Overhaul.esp  [Version 1.33]30  OOO-Water_Weeds.esp  [Version 1.33]31  Mart's Monster Mod for OOO.esp  [Version 0.9.8b5]32  Mart's Monster Mod - Additional Enemy NPC Vars.esp  [Version 3.5.5b4]33  Mart's Monster Mod - Diverse Creature Skins.esp  [Version 3.5.5b4]34  Mart's Monster Mod - Hunting & Crafting.esp  [Version 3.5.5b3]35  Mart's Monster Mod - Looting NPCs & Creatures.esp  [Version 3.5.5b4]36  Mart's Monster Mod - Zombies for Body Meshes.esp  [Version 3.5.5b4]37  Mart's Monster Mod - Safer Roads.esp  [Version 3.5.5b4]38  Mart's Monster Mod - Vindasel.esp  [Version 3.5.5b4]39  Mart's Monster Mod - Foxes.esp  [Version 3.5.5b4]3A  Mart's Monster Mod - More Wilderness Life No Gates.esp  [Version 3.5.5b4]3B  Mart's Monster Mod - City Defences.esp  [Version 3.5.5b4]3C  Mart's Monster Mod - Extra Wounding.esp  [Version 3.5.5b4]3D  Mart's Monster Mod - Friendlier Factions OOO+FCOM.esp  [Version 3.5.5b4]3E  MMM-Cobl.esp  [Version 1.69]++  EVE_StockEquipmentReplacer4FCOM.esp3F  Apachii_Goddess_Store.esp40  Apachii_Heroes_Store.esp41  Knights.esp42  Knights Vwalk.esp43  EVE_KnightsoftheNine.esp44  The Lost Spires.esp45  Harvest [Flora].esp  [Version 3.0.0]++  Harvest [Flora] - Shivering Isles.esp  [Version 3.0.0]46  EVE_ShiveringIslesEasterEggs.esp47  P1DkeyChain.esp  [Version 5.00]48  Salmo the Baker, Cobl.esp  [Version 3.08]49  Toggleable Quantity Prompt.esp  [Version 3.1.1]4A  RealSleepExtended.esp  [Version 2.3.4]4B  TeachSpell.esp4C  SupremeMagicka.esp  [Version 0.89]4D  SM_ShiveringIsles.esp  [Version 0.86]4E  SM_OOO.esp  [Version 0.89]4F  SM_MMM.esp  [Version 0.89]50  SM_COBL.esp  [Version 0.86]51  SM_EnchantStaff.esp  [Version 0.80]52  SM_Scrolls.esp  [Version 0.84]53  SM_SigilStone.esp  [Version 0.83]54  MidasSpells.esp55  Druid.esp56  SeductiveIdles.esp57  Let There Be Darkness - Cyrodiil.esp58  Let There Be Darkness - Knights.esp59  Let There Be Darkness - Cyrodiil + SI.esp++  Item interchange - Placement.esp  [Version 0.76]**  _Ren_BeautyPack_full.esp5A  Tabaxi Race 2.0.esp  [Version 2.0]5B  Tabaxi_Race_BAB_Robert.esp5C  Toaster Says Share Faction Recruitment.esp5D  CM Partners.esp5E  Aliyah.esp5F  Tamara.esp++  Cobl Filter Late MERGE ONLY.esp  [Version 1.53]60  Bashed Patch, 0.esp61  Shaman Clothing.esp62  SetBody.esp63  DesuChan's Kawa-Khajiits.esp64  CM Partners Friska.esp65  SedaArmor.esp66  Journeyman_armor.esp

I ran into this a few years ago with the exact same dead drop, and never did figure out why it happened. The only thing I was running at the time that you're running was OOO, so it's either an OOO quirk or something from vanilla.

Sorry I'm not more help, but maybe the bit of information and the bump will bring you to the attention of someone who's more sure what's happening.