I've ran into the following issue:
my menu is a window which opens from a regular scene. To preserve a nice screenshot I use the following code just before I display that window:
.Msg("Something went horribly wrong!")
The image thumbnail is set in Project Manager to 176x176, Personal Savegames are set to Yes, Save directory as saves and Rich Saved Games to Yes.
At work I have W7 64bit, at home Vista 64bit (don't ask me why
In both cases the code runs with no problem, however on W7 only black rectangle is stored instead of thumbnail image.
On my home Windows Vista, the thumbnail is correctly stored and shown. As I use SVN so it's guaranteed both installations are the same. No error in log either. It seems that for some reason the method returns just a black rectangle.
One thing to mention is that at work I have dual monitor setup but I've played the game on the first (main) monitor.
UPDATE: I've tested on my W7 64bit laptop and savegame thumbnails work correctly there! I've tried all possible combinations and the issue is connected to dual monitor setup.
No matter which monitor I run the game on, as soon as I have dual monitor setup,
no thumbnail (or black square instead of proper image) is stored.
After some more testing, this issue happens only when either window or fullscreen is on the second monitor.