Hi all,I've been struggling with this all week. I have ACAD 2009 (and 3ds Max 2010 which works fine). I'm working on a Lenovo T60p laptop and my graphics card is an ATI MOBILITY FireGL V5200. I have 4G RAM, though this machine with Windows XP, 32 bit can only use 3G of it. After using the program for months with no problems, it started to spontaneously close after opening a drawing and clicking my mouse's scroll wheel. I have a Logitech mouse, but also tried a Dell mouse and experienced the same issue. When it closes, I mean to say that there is no notification, no asking me if I want to save the drawing, no "fatal error". It simply vanishes from my screen. When I reopen it, it recognizes that it did not close properly.I checked mouse drivers (up to date), and CAD and normal graphics card drivers (updated after the problem began).  The files work just fine on other computers.I've uninstalled and reinstalled the program and don't think I'm up for it again. Any suggestions?thanks!