Strange screen display behaviour

Hi

Since I got my new system (Home Premium x64) several weeks ago I have had no end of trouble with strange behaviour from my display after the computer has been in Sleep mode for several hours. Windows jump around on the screen, maximize and restore spontaneously and so on. Refreshing from the Desktop several times is sometimes enough to stop it, more often I have to reboot. Sometimes 2-3 reboots are needed. Sometimes 2-3 days will go by with nothing happening, but every time I think I have isolated and fixed the problem it comes back. Most often it's necessary to reboot 2-3 times a day.

I can run sometimes run some programs when I come out of sleep, but Firefox (if anything) will nearly always trigger the behaviour. If the computer has been "sleeping" for only an hour or two, this doesn't occur. It's mainly first thing in the morning. I leave my system on overnight for virus and other scans and automatic updates.

I have installed all the latest drivers for my graphics cards (Radeon 4800).
My monitor is an old CRT Samsung SyncMaster 950p Plus - Vista recognised it and the "driver" is okay. I also tried putting my husband's LCD monitor on my system - it did the same thing so it's not the monitor. I have checked my cable connections which seem fine but I have ordered a new cable in case, but not hopeful.
I have a modified theme running, changing resoluton and refresh rates, have tried returning to all defaults to no avail.

Any ideas out there?? I can live with this as my system reboots really quickly, but it's annoying not being able to isolate and fix this. Any help greatly appreciated.

Simple soulution dont put your computer into sleep mode. i have never ran or trusted sleep mode as i have know people that have had issues with it on XP.

so my suggestion would be to turn off sleep mode and see if it still happens.

It is not your cable. Have you looked at the tutorials section.
http://www.vistax64.com/tutorials/63567-power-options-sleep-mode-problems.html

Thanks guys. I have been through the tutorial and modified a few things, but Sleep is only part of the problem. It also happens when the computer is active, mainly when I start Firefox, or even as I am using it. For example, I was typing a reply when FF maximized itself. A few moments later it restored itself etc. etc. It also sometimes happens when I access Control Panel. Those are the only two things (so far) that I have found to cause the strange behaviour, but as it's not remotely consistent it's very difficult to pin down the cause. One day I might stumble across the answer!

Robin