What is causing this lopsided face / geometry error?

[BFG99]

I'm an experienced Oblivion mod author (see my signature line) who is reinstalling Oblivion after a 3 1/2 year hiatus. I've spent dozens of hours picking out the best mods, carefully Pyffing and DDSopting and TES4Editing and Bashing everything, only to find that, in-game, all of the characters are suffering from weird lopsided faces / facial geometry errors. That's after it looks perfectly fine during character generation. And I am pulling my hair out because, after 10 hours of debugging efforts, I cannot figure out the root cause. (The really annoying thing: I remember it also happened 3 1/2 years ago, and I fixed it then...but I cannot recall how!)

 

To see the error, look at the linked JPG below. You can see a weird growth on the right side of the character's face, in the space between the face and the hair. There is no similar growth on the left side, though there are similar, smaller, geometry errors in the left cheek not visible in the screenshot.

 

Short of a full reinstall, I've done absolutely everything I can think of to fix this, including doing all of the following at the same time:

• Removing all of the Pyffi'd, DDSopted, and repacked BSA files from my Data folder, and reverting to the original, untouched, vanilla BSAs
• Removing all loose Meshes, Textures, and other folders from the Data folder (to ensure I was only using the meshes/textures in the original BSAs)
• Disabling every mod, even the unofficial patches and the Bethesda DLCs like Shivering Isles
• Checking dates on all files to ensure they will load in the correct order
• Deleting Oblivion.ini to force a revert of that file, and making sure the BSA list is correct
• Turning off OBSE, Wrye Bash, ArchiveInvalidationInvalidated, etc.
• Restarting the game to see if it would impact a second character

I know about the facegen errors that can occur if you alter the Oblivion - Misc.bsa file in any way, so I've been using the original copy of it all along. I also know about the errors that can occur when you Pyffi hair, helmets, or anything else with an EGM file - but, even though I used Pyffi Automater which is supposed to skip those, the error still occurs even when I go back to the non-Pyffi'd versions. I did have Blockhead installed but removed it after removing all mods that needed it. The only alteration I can't eliminate is the 4GB patch I added to Oblivion.exe.

 

So, based on the above, and the fact it still occurs even when I revert to vanilla assets, does anyone have any ideas? Is it possible it has something to do with my graphics card or driver?

 

My specs:

DVD-Based Oblivion GOTY edition, with final official patch

Intel Core 2 Duo P8400 2.26GHz

4GM RAM

Nvidia GeForce 9600M GS 1GB (yes, it's old), with the final official driver compatible with that card (R340)

Windows 7 Pro x64

DirectX 9 x64

 

Load order while bug is in effect:

Oblivion.esm

...aaaand, that's it. Yes, really.

 

 

Image of issue at: http://i801.photobucket.com/albums/yy295/jtrevor99/ScreenShot0_zpsgsxqrb5k.jpg

Edited December 18, 2015 by BFG99

[BFG99]

Anyone?