"You need to restart you computer" Message during upload

[psyks]

Ok, I've had my imac for a few weeks now with only one problem that's recently occured and the problem is this.
During the process of uploading attachments to emails or posts or uploading anything to putfile, the screen dims from the top and I get a multilingual message telling me to hold down the power button for several seconds. This first occured while uploading a .zip file.
I have absolutely no idea what to do, and would be extremely grateful if anyone could offer any help. Thanks

 

[dukebound85]

is it a kernel panic by chance?

http://support.apple.com/kb/HT1392

 

[Tallest Skil]

That's a kernel panic all right.

Strange presentation, though...

 

[psyks]

Yes, that's the one. Are there any usual steps to take to solve this?

EDIT

On closer inspection, it appears that this only happens while using Opera, so unless anyone has any ideas, I can always install firefox.

 

[porridge111]

no need to download firefox or anything like that. just use safari! If the kernal panics only happens when using opera, than you've figured out where the problem is. just use safari instead