Imac freezes since mountain lion upgrade, i set to never sleep and then it is ok. any ideas what is going on?

Question

This may be the same issue as some other discussions but I have a few different circumstances. I upgraded to Mountain Lion a few weeks ago and all seemed to be ok. Then I got an upgrade notice for Itunes last week and installed the update. Since then My mac started freezing after coming out of sleep mode. The mouse was active but when i selected programs from the dock the icons would just bounce and nothing would open.The only way to revive it was to do a restart with the power button. Then the system would be fine until it went into sleep mode .After reading through several disussions it seems many people are having similar issues with very few fixes to the problem. I am not very savvy on mac O/S so I am in the dark as to where to begin to troubleshoot this problem. Since the freeze ups always occur after coming out of sleep mode I set my computer to never sleep which has worked to stop the freezing but I am not sure how good it is for my system to be running all the time. I would appreciate any input on this problem. My Imac is a 2008 intel with 3 gig ram

Answer 1

Please read this whole message before doing anything.
This procedure is a diagnostic test. It’s unlikely to solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.
The purpose of the test is to determine whether the problem is caused by third-party software that loads automatically at startup or login. 
Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards. Boot in safe mode* and log in to the account with the problem. The instructions provided by Apple are as follows:
Shut down your computer, wait 30 seconds, and then hold down the shift key while pressing the power button.
When you see the gray Apple logo, release the shift key.
If you are prompted to log in, type your password, and then hold down the shift key again as you click  Log in.
*Note: If FileVault is enabled under OS X 10.7 or later, or if a firmware password is set, or if the boot volume is a software RAID, you can’t boot in safe mode. Safe mode is much slower to boot and run than normal, and some things won’t work at all, including wireless networking on certain Macs.  The next normal boot may also be somewhat slow.
The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin. Test while in safe mode. Same problem? After testing, reboot as usual (i.e., not in safe mode) and verify that you still have the problem. Post the results of the test.