I can't remember exactly what to do. I never had a problem with this as I was lucky to get it right from the beginning when it came to Races. Yes, it is a problem connected to the way Oblivion works with races and adding stuff to them.
If you get your Wrye Bash working I think that will sort it with the Bash patch. But check the readme's for the mods you got that changes Birthsigns/races or beautifying mods.
Myself I am giving up. I been modding my games for years so I have some experience. Installing my Oblivion for 55+ hours now - tweaking and testing to work out the bugs and problem between mods. Tried to fix my Lod problem in Elswyer - and now it is totally kapput. It's gremlins everywhere. :violin: