Nalia and Imoen just went from level 20 to 21, and they didn't get any extra spells! The manual says they should get an extra level 6 and level 7 spell. What gives?

MAYBE...the XPCAP remover that I installed when I played regular BGII is screwing things up somehow. I will try removing that, or even nuking the game and reinstalling...if those don't work, I give up...any ideas?

The manual and actual game play dont alway match. I would not worry about it, Unless they never get any spells (as their levels continue to go up). SOA has several mistakes (thus the existance of Baldurdash). I imagine TOB is the same way.