I have found that as i play tthrough the game certain characters are said to be "busy" when i try to speak to them. This isnt usually a problem however sometimes these characters are crucial to the game is there any way to get them to speak to me. I know that walking out of the room and then walking back in again usually fixes it but it doesnt allways. I have found this problem more aparent in throne of bhaal. Thanks

Download the latest Bioware Official patch. It has a fix for that problem in particular. If the patch doesn't work then someone else I'm sure has some idea about what you should do.

I'm guessing you have windows xp? if so, then yeah, the "busy" thing is common and can be solved by the patch.