[spooky]

Now that i have had time to think about it for a while... i remember a couple of mates had a similar problem.......it all boiled down to a badly fragmented hard drive......infact one had bad sectors on the drive........ every time a large image was created a coster was produced... smaller images were fine...have you defragmented your drive recently?

Apart from that the only other thing that springs to mind is other programs you may have running in the background, interrupting the processor... have a look with regedit and dissable anything you dont need.....

It may sound like im clutching at straws now and to be honest i am..... but things like this bug me until i know the cause.....