Been using Snow Leopard on a 24" 2.4Ghz iMac pretty much since the day of launch. Initially was very pleased, no real problems, seemed to run even smoother than regular Leopard, however, recently, my system has developed a bunch of issues, particularly when running word and/or transmission (possibly other apps, but I have noticed with these two so far). The main problem is, very randomly, the system will lock-up. After the lock up, you are able to use open apps, ie Transmission, Word, Safari, Finder, etc, but they do not function correctly...for example Word - You can click into documents, but any keyboard strokes are completely ignored. Safari - You can browse links on default start page, etc, but you cannot create new tabs or type anything into the address bar. Finder - You can browse folders; but you cannot perform any functions such as dragging to trash, etc. Also worth noting, it the main menu bar at the top of the screen continues to say either "Word" or "Transmission" etc, regardless of what application you are in. Clicking on any applications icons in the dock has no response unless they were already running. The system is unable to shut down or log off, and you cannot quit apps. The only option is to do a hard reset via a power off. Note: My system is set to never sleep. There is no screensaver. Any advice would be gratefully received. I'm a fairly new mac user so i'm not aware how to view log files etc., which may identify the problem. Many thanks in advance.