If you havnt already done so, fully remove Kazaa and Kazaap, download Kazaa lite, here:
http://www.kazaalite.tk/
The download and run Spybot: Search and Destroy, which you can get here:
http://spybot.eon.net.au/
Run that, remove any problems it finds.
Fool around with Internet options, as suggested. Make sure your internet security isnt on max.