You have to repair your Outlook.pst file.
Sometime it shows up as the envolope in the task manager saying outlook is synchonizeing folders and won't leave for 10-15 min. meanwhile cursor is the only thing that moves. keystrokes don't respond, even task manager is really slow to respond if it does at all. hard drive stay on all the while it is doing this. Or it will not close until it is done doing whatever it is doing.
Then when it is finished, all the keystroke you made during the problem, proceed as normal, except by this time your more frustrated then a wet hen.
THE OUTLOOK.PST file has errors that need to be fixed with a progam you already have! OUTLOOK is fine, thats why the diagnosis comes back good and thats why an uninstall and reinstall don't help because the problem is not with outlook.
First you should run an error checking program like chkdsk
on your C drive properties error checking.
Then find C:\Program Files\Microsoft Office\Office12\SCANPST.
Then find your outlook.pst files
It will find errors even afters running a few time. run it as many times as it takes until there are no more error, on all outlook.pst files
Go back to outlook and enjoy the program that use to work fine and does once again.
Don't bother to thank me for the fix.
Jim