Hey, I've got a character using the Anti-Pally kit from Tactics, and it WAS working out great. But now, my kit is changed to Kensai, and I can't change it back.

Has anyone else had this problem, and if so, how did you fix it?

I havent had this problem but you may be able to use shadow keeper or another editor to change it back.
Have you reinstalled the game or installed any new patches?
I'm sorry if this is a bit obvious. :(