alerum68 and EF:
Let me try and explain a little better.
I compile my own dll. This new one is based on 3.19, includes BBAI, BULL, DCM, Influence Driven War, Assilmilation plus a few other small dll mods. See the link in my sig for more info. All the XML from these mods is also merged, of course. Surprisingly, there is very little python in these mods. The one mod that is very python intensive is Inquisitions, but I've not merged this yet. So, I've basically done all the dll merging and compiled and merged all the XML. Then, I've installed BUG 4.0 to it's own mod directory, and then copied the python folder from (and the other directories like customdomadv, usersettings and res) to the Merged Mod's Asset dir. I've then done a winmerge on my old mod version (which included BUG 3.6), and then copied the old non-BUG bits and pieces to the pyton folders.
At this point, AIAuto runs the game to the end without a single python error - but the interface screens are slow, like I described.
(Note: I've just noticed that I have both a Gamefont.tga and Gamefont_75.tga - I shouldn't have both, but could this be the cause?)
I'm afraid I don't have enough time right now to test any alternatives, as I'm going on a business trip for two weeks.
Cheers!