Our 6 month old iMac will beach ball for 3-4 min with any applacation we run. Sometimes it will just end the app and turn off other times it will keep beach balling. It will freeze while listening to or watching movies on front row. When we restart it it sometimes will have a folder with a question mark pop up instead of the apple. It has come on on it's own after being turned off and has been running slower. We have tried doing a clean install and it still hasn't shown any improvement we also did the latest update on os. I have read a lot of scary things about the new updates. Can anybody help us?