Alt+Tab?

If I try to alt+tab to Windows, everything is OK, but if I try to alt+tab back to the game again, it takes forever. Sometimes, the game appears after a couple of minutes wait, sometimes it doesn't appear at all, or so it seems, because I have not waited more than 5-6 minutes (honestly, that just ruins the point of multi-tasking ).

I read about this problem in the beta forums, but I haven't found a solution.

I run Win Vista 64(latest upd), 8gb ram, 8800gt (latest drv), 2x3ghz amd

I do not experience these problems in other games.