I recently downloaded a hair mod, Babe Hair, and I noticed that only the hair from the Beautiful People mod was showing up.
Remembering that I'd had this problem before (kind of) I remembered that it had something to do with TESGecko.
So I opened 'er up and merged Beautiful people, Babe Hair, and a couple of other mods I had on there too.
However, seeing no effect from this, I created patches for Beautiful people to each hair mod and applied them to Beautiful people.
Unfortunately, not only did this not work, but now my game crashes when I load my game.
For some reason, one of my mods seems to be conflicting with OOO, but it was running fine before I applied the patch so I doubt that's the case.
So now I'm sitting here, scratching my head, wondering how applying patches to a mod would make it conflict with a mod that does something totally different.
Oh, and here's my load order:

Oblivion.esm
Oscuro's_Oblivion_Overhaul.esm
Toaster Says Share v3.esm
Unofficial Oblivion Patch.esp
UOP Vampire Aging & Face Fix.esp
LoadingScreens.esp
PCSoundInnocent.esp
Adonnays Ranger Coats.esp
Living Economy.esp
ExnemEyeCandy.esp
BlackLuster.esp
CapesandCloaks.esp
KDDwemerSpectacles.esp
Scarves!.esp
ScimitarMod.esp
Wyrmfang.esp
Black Plate Armor.esp
Oscuro's_Oblivion_Overhaul.esp
OOO-No_Guild_Ownership.esp
OOO-DLT_Remover.esp
OOO-Armor_Perks_WearRate_Repair.esp
OOO-BirthSigns.esp
OOO-Combat_Skills_Perks_Marksmanship.esp
OOO-DaedraLord_Quests.esp
OOO-Dangerous_Traps.esp
OOO-Deadly_Combat.esp
OOO-DLT_Immersion.esp
OOO-Magic_Effects+Enchantments.esp
OOO-Magic_Effects+Spells.esp
OOO-Magic_Game_Settings.esp
OOO-Potions.esp
OOO-Container_Trap_Instant_Effects.esp
LoadingScreens-OOO.esp
24HrArenaAliveV2Towers.esp
gardening.esp
Alternative Start by Robert Evrae.esp
MidasSpells.esp
No psychic guards v1.2.esp
RenGuardOverhaul.esp
RealisticLeveling.esp
Seph's new animations.esp
actors_in_charge.esp
ActorsInEmotions.esp
DMC Stylish - Specialanims.esp
tkHairPack01.esp
babehair_EV.esp
Beautiful People.esp
1em_Vilja.esp
OOO-Respawn_Month.esp
OOO-Respawn_Two_Week.esp
OOO-Magic_Script_Effect_Fix.esp
Duke Patricks - BASIC Script Effect Silencer.esp
Streamline 3.1.esp
Unofficial Oblivion Patch Sup.esp
Andrews_No_Quest_Items-6729.esp
Fall hair 1+2 V.3.esp
Custom-vilja1.esp
Evantal's Dual Wielding.esp
DMCDanteClothes.esp

Have you used Mod Deisolation when making your patch? If not, you've created a file that will always crash the game on load.

(Which is what you're describing, so I guess that's the most likely issue.)

I don't even know what Mod Deisolation is, so probably not.
Hm. I might have an idea. Give me a minute.
Edit: If I deactivate Beautiful People, the game still crashes.
More thought is required here methinks.
Edit 2: I deleted the merged file I created and all the patches that I made using TESGecko and the game still crashes.
Is there a different problem here?

Short version: Use Wrye Bash's "Esmify self" on any source mod you want to make a patch for. After you've done, you can use "Espify masters" on your patch, and if you want to work on it again, use "esmify masters".

Without Mod Deisolation .esp files can't depend on .esp files, which means a "missing info" error occurs, which will crash the game (missing info = the file is referencing something that can't be found anymore, due to being part of another .esp file).

To get your game playable again, try to recreate the mod setting before any patch attempts. I'm sure there's somewhere a somewhat broken mod in there.

Oh I see. I'm afraid I've never really got the hang of using Wyre Bash. I'm not entirely sure how to use it if I'm honest. I read the online manual and I get how to do some things, but it's main feature (creating a bashed patch) continues to alude me.
What I was going to do was open the construction set with Beautiful People, and manually add each hair to Beautiful People from the other mods. That takes a long time however, so if I can use Wrye Bash to make a patch, then I'll give it a shot.
Anyway, I'm re-downloading Beautiful People and I plan to replace all the files with these fresh ones.
Interestingly however, if I deactivate all of my OOO related mods, the game will load, but I no longer have a body or face suggesting that Beautiful people isn't working at all since I use a race included in Beautiful People.

For learning Wrye Bash, http://www.tesnexus.com/downloads/file.php?id=35230. I've been using Bash for years, but I still found it helpful.

Wrye Bash is easy to use. The proof? Well, I use it!

I'd recommend skipping Beautiful People entirely. It doesn't play nicely with other mods affecting eyes etc. Use Cobl Races or RBP instead.

Thanks, it looks pretty helpful
Anyway, I've replaced all the broken mod files for Beautiful People with fresh ones and the game is running just as it was before.
Now I just need to find some way to get all the hair mods to work together.
Wyre Bash doesn't seem to be able to do it, but I'll keep searching.
Thanks!

Well, I'll see what I can do about getting the hair mods to all work in harmony. Otherwise, I guess I'll download the mod parts seperately.