I recently upgraded to FCP 5 from FCE. I started work on a project and am experienceing a weird problem. On certain frames of certain clips that I have applied effects to, there is noise (white pixellation). I have no idea why this is happening. I have exported the video, and sure enough the noise shows up. Anybody have a similar problem or know what I can do to fix it?

I don't suppose you could show us please, with a screenshot? (Command-Shift-3 will take a picture of your whole screen. A file will appear on your desktop called "Picture 1")

without noise...
http://www.wakeeuphoria.com/pics/wonoise.jpg


with noise...
http://www.wakeeuphoria.com/pics/wnoise.jpg

Has anyone experienced a similar problem? I have no idea why this is happening.

It looks like you're running Panther or an earlier Mac OS version. According to Apple's current FCP page, it requires Tiger to run FCP5. (http://www.apple.com/finalcutstudio/specs.html?finalcutpro)

But, since you got it installed, I could be way off.

Not knowing what specific effects you applied, my general inclination would be to use the Render Manager (under the Tools menu) to delete those render files, and force a re-render of the sequence.