Not sure if this is the right topic, because the problem is somewhat odd, but I suppose this is the closest it gets. So, here it goes:
I recently upgraded my PC (please see full config below) with a Sapphire Radeon HD6850 video card, having previously used a very old XFX GeForce 8500GT. I knew that Nvidia and AMD/ATI drivers often conflict with each other even if the previous one has been supposedly removed; so, when I installed the new card, I performed a fresh, clean Windows 7 (Home Premium x64) install from scratch. The card was initially installed with AMD Catalyst 10.12 drivers for Windows 7-x64, and last week they were upgraded to version 11.1, with no apparent change.
I use my desktop at my monitor's native resolution of 1680x1050 (it's a 20" Samsung T200M). I don't use a screen saver, but the system is configured to turn off the monitor when idle for 10 minutes. When this happens and the monitor is turned back on by user activity, I find that all windows that are not maximized have been resized to 1022x736 and stacked on the desktop's top left corner (position 0,0).
This also happens with windows that are completely hidden behind larger ones, if I work on the top-level window for long enough (about 10 minutes). Windows with the current active focus are not resized as long as I keep working on them, no matter for how long. It looks like Windows or Catalyst is storing always the same window size and position data for all windows, and always uses those values (1022x736 and position 0,0) when forced to redraw them after some time.
This is my first experience with an AMD/ATI card; previously, I had always used Nvidia cards, so I'm not yet familiar with Catalyst's idiosyncracies. Yet I have thoroughly examined all options in Catalyst Control Center and found nothing that could explain or solve the problem. I couldn't find anything related searching this forum or the Web either. I strongly suspect that Catalyst is to blame, because the problem started when I installed the new graphics card, and had never happened with my previous Nvidia cards.
Obviously, this is not a critical problem, but it's annoying nonetheless, because one tends to dimension and arrange the windows one is working with on the desktop in the most convenient or preferred way, and it's a hassle to have to do it all over again every few minutes.
Any hint? Is this behavior expected? "Not a bug but a feature"? Any obscure configuration parameter I could try? Thanks for any tip you can give me.