Have you installed anything new in there, like RAM?
RAM is one of the major causes of this screen.
Lacking details as to what Mac you have does not help the troubleshooting process.
If you installed 3rd party RAM, remove it and put the original back in.
For some reason for the last day or 2, my imac screen will be filled with a shaded transparent screen with a message saying something along the lines that i must restart my computer. my system is the Mac OS X leopard 10.5.8.
It will happen at random times, sometimes it will take an hour, sometimes couple of minutes. Most times it happenes right when i click on say a file or a link or anything. But still happens when nothing is clicked or anything.
Any ideas whats going on? anyone had this problem?
Any feedback will be much appreciated.