I've encountered a strange bug with Kelsey, made all the stranger since he isn't even in my party. I'm in Saradush with ToB, my party consisting of myself, Imoen, Minsc, Sarevok, Jan, and Viconia, and I'm in the romance with Viconia. However, there's a strange bug with Viconia's flirts (I have the flirt pack installed): it shows Viconia's portraits, but it displays the text and plays the wave files for Kelsey's flirts. I would have uninstalled Kelsey to see if that would fix things, but as far as I can tell, there is no way to uninstall him, and I don't know enough to try deleting files.
In case it's a mod conflict, here is, in no particular order, a list of all the mods I have installed (and I'm afraid it's quite a few):
Ease of Use
BG2 Flirt Pack
Banter Pack
Crossmod Banter Pack
Imoen Romance
Edwin Romance
Kelsey
Keto
Fade
Saerileth
Yasraena
Tashia
Amber
Xan for BG2
Edited to include Xan, who I just downloaded and installed.