I am having problem with compiz-fusion icon in fedora 14...

I have installed compiz, but when I click the compiz-icon to start it.... the system logs off and again asks password...

Same thing I have done in my HP laptop, but in it, its working.. The problem comes in my pc only... I also want some help for knowing, how to add compiz-icon in the startup of the kde session...in "FEDORA 14", so that when I login using kde, the compiz-fusion automatically starts with this process... Somebody please give me a solution...
Frnds I am having problem with the nvidia driver for fedora 14..
Whenever I start compiz.... The screen blacks and logs off the session....
Pls tell me how to correct the problem.... and the steps to install the nvidia driver...