I guess there is a problem with some mouse driver (Genius?) or you use some desktop enhancement? If you update file outside PSPad and return back, PSPad shows you dialog with reload file confirmation. This dialog in your case is hidden under PSPad Windows.
Try latest 4.5.3 build. Try swith to another application and back to PSPad, the dialog shoud appears -- <http://forum.pspad.com/read.php?2,41622,41627> PSPad freeware editor http://www.pspad.com
