I'm running two XP SP3 on a reasonably current desktop with 4 GB and an ASUS Radeon 4350 graphics card with 512MB. The card drives two Samsung SyncMaster 2443 monitors, one from analog RGB port, the other from a DVI port. I've been using Firefox since v.3, but sometime around v.8 or v.9, it began to have problems when ever I had a Firefox window open on the analog video port. (I'm current with v.27.0.1) The window 'appeared' to freeze - clicks, scrolling and the like failed to produce a re-drawing of the window's content. However, if I dragged the window over to the other monitor running off the DVI port, the Firefox window would re-draw itself with the new content. This behaviour told me two things. On the analog port the Firefox window was still alive, and responding to keyboard and mouse inputs, but not displaying the results. Secondly, the problem was related to the Firefox - RGB interface. Oh! I forgot to mention: Firefox was the only application exhibiting this behaviour. A support session with ASUS produced no solution. After searching several related Mozilla support issues, on a problem closely related to mine someone suggested turning off the hardware accelerator, and re-starting Firefox (Tools > Options > Advanced > General > "Use hardware acceleration when available"), which I did. Poof! Problem solved, case closed. Except, Why? Is this just because of my hardware setup? Or Firefox - I generally have 6 to 10 windows open at a time, some with several dozen tabs (I'm a software architect, so tend to keep a lot of context on the desktop). I'm glad I can scroll Firefox now on my other monitor, and click buttons and be able to read the response, but I think there's a defect here somewhere...