Screen-saver resizes my windows I have an iMac(27" from 2010) and while running Lion I tried to HiDPI modes that gives me 1280x720 and larger text. I did change back to 2560x1440 long before upgrading my system to Mountain Lion.

If I use the screen saver, or switch to the "select user to login" main screen, and then back to my user account, my windows are resized to fit inside a rectangle that looks like 1280x720. This behavior happened in Lion too and the upgrade didn't change that.

Any idea on how I can get rid of this behavior? I haven't found any .plist file to delete that seemed relevant.
I changed the resolution to 1024x768, logged out, rebooted, logged in. Changed to 2560x1440 and logged out and rebooted. That seemed to have fixed it.

EDIT: No, it didn't fix anything.