I just installed Win32::GUI and this seems to be working ok for me. It just redraws the green rectangle with the text at the top left from left to right. Btw, I changed mine with a $mainWindow->label1->Hide; before the animate call and used -show => 1, in the Animate call so that it just redraws every time you click the button instead of toggling every other time. It also worked from bottom to top and right to left for me (and probably other combos). I'm doing this under cygwin.