Microsoft Document Cache has stopped working

While opening office documents from a SharePoint 2007 or 2010 site on a Win 7 client using IE9. We were continuing encountered an error when saving the document.

Microsoft document Cache has stopped working.

After hours of research and googling with lots of suggestions as offer by the sites below.

http://community.office365.com/en-us/forums/148/t/178459.aspx

We tried : 

-Removed local document cache files from the Office Upload Centre Settings and from C:\Users\username\AppData\Local\Microsoft\Office\14.0\OfficeFileCache
(This worked temporarily is has been marked as an answer by MS but the problem comes back after restart or after log off.

-Disabled MSOSYNC.EXE from Office Start Up using MSConfig
-Checked registry settings in 
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run and 
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Common\Internet\OfficeSyncProcessAutostart

as recommended here http://social.technet.microsoft.com/Forums/office/en-US/79e88e72-e9a2-4740-a41e-dbec4511ec59/disable-upload-center-via-oct-2010?forum=officesetupdeployprevious

-Disabled Office Document Cache handler add-on from IE9.
-Removed MSOSYNC.exe from task manager processes.
-Changed Word's Save options to use Server Draft location
-Disabled IE Office Document Cache Add-On
-Remove MSOSYNC.exe and MSOUC.exe from C:\Program Files (x86)\Microsoft Office\Office14

All to no avail.  Problem was still around.

It turns out that our problem was quite simple in the end but somewhere on the line someone had not installed Office 2010 SP2 was not installed properly by CSC.  

Basically, the version number reported by Office Client in the File - Help screen is not as accurate as reported by the OffCat tool. Neither is the version shown in the Add Remove 

Program.  To really know which version, use OffCat tool by MS from here http://www.microsoft.com/en-gb/download/details.aspx?id=36852

The tool reported it was not even SP1 properly.  Download SP2 http://support.microsoft.com/kb/2687455 and then install as Admin.  Voila problem was address by the SP2 update.

Moral of the Story.  Use OffCat to find out which exact version and patch update of Office 2010 you are running and make sure SP2 is installed.