I also think that this may be related to graphics card power. MM9 works fine on my desktop - a not particularly whizzy P-III 650MHz 384MB RAM and an ATI Rage 128 GL AGP card. However, if I alt-tab to bring up another application in the background (like IE for example) then when I alt-tab to bring MM9 back and the Lithtech engine is running (because I'm outside and it's rendering those 3d graphics?), it'll hang.5 will get you 10 that it's a graphics resources problem sweitching graphics modes whenever the MM9 Lithtech engine's started up. Very annoying.