I've been having some trouble with one of my Delphi 2010 projects lately. It seems that sometimes, when I have a form open as a modal dialog, the app stops showing up in the ALT-TAB list until I close the dialog. It's still in the Taskbar, but not in ALT-TAB, which means I can't switch to it without using the mouse.

Running under Windows 7, 64-bit. Has anyone seen this before? Any idea what causes it and how to fix it?