I've been using my iMac for 3 months now and 4 days ago, it began doing strange things. After a short time 10 - 30 minutes the dashboard button - F4 stops bringing the dashboard up, the cmd and tab stops working bringing up the list of open open apps, and expose and spaces stop functioning - the shift arrowsto move between spaces does not work, and the active screen corners have stopped working. I have to use the dock to find open windows and its a PITA. Restarting solves the problem, for only for 10 - 30 minutes. The itunes buttons on the keyboard still work, but the brightness and darkness dont. I can use the cmd, alt, ctrl and shift keys for editing and selecting text when word processing, but they dont seem to work in conjunction with the function keys. I have not installed anything in the last week or 2 that could do anything. ( I also have no idea where the Fn key is - unless that is for laptops ) Any help would be much appreciated. Mac OS X 10.5.2 software up to date 2.4 Ghz intel core duo 4 Gb 667 Mhz DDR2 SDRAM 320 Gb drive partitioned smaller one for windoze games and 2 external drives FAT 32 as externals. non apple mouse as the thing lasted a month.