I remember having had something similar a few times. The one that jumps to my mind right away was in IceWind Dale. Near the end when you got teleported back to TenTowns, the computer didn't release the controls to me after the scripted event. My party started complaining after a while ...
http://www.gamebanshee.com/ubb/wink.gif
Anyway, I see either two options: either you reload a prior game and try again, as this solved the problems I had in these cases. Or, you might want to delete the cache files, as one or more may have become corrupted.