I was afraid that it would've come to that. The weird part to all this is that I have used BWS and only two mods were added between the end of BG1 and the start of BG2. I made a save file just before I talk to Belt at the end of BG1, stopped the game to install Kagain ToB and Improved random encounter, then start the transition to BG2. Everything else was kept the same (I saved my .ini from the package selection in BWS). I also did a full wipe of my \BGII - SoA\ folder before installing any additional mods. I suppose there's no guarantee it would work even though all the old savegames can be loaded just fine.
Well, thanks for your help, Herr Imp.