Microsoft Office Upload Center cache constantly needs repair

I originally posted this in Office365 as that was the forum I was sent to from my Administrator panel. However, they have said to post here instead. So here goes.

Since a few days ago (around the time I installed Lync Basic instead of Lync 2010), the Microsoft Office Upload Center constantly needs repair. I have deleted the caches in User/App Data/Local/Microsoft/Office/14.0/OfficeFileCache and also /15/OfficeFileCache

It is the one in /15.0 that is the issue (now up to OfficeFileCache - 10.old).

When I try the repair option, it says something is accessing the cache and please close all Office apps. Even if there is no Office app running. I stopped Lync automaticallly starting, rebooted and still the same. I have to close in the systray SkyDrivePro and SkyDrive and then the Repair can continue. Then the error is cleared.

I can leave it for 10 minutes and the Upload Centre icon sits in the systray quite happliy. Until I open Windows Explorer and click on the SkyDrivePro icon, I can see my SkyDrivePro files in Explorer as normal with the green ticks, the SkyDrivePro icon in systray says it's up to date (nothing being processed) and then the Office Upload Center error comes back.

"The Microsoft Office Document Cache encountered a problem and needs to be repaired."

I have Office 2010 on the desktop and Office365 as my company's main work environment.

I'm baffled. How can I stop this happening? Thanks.

also

I have Office 2010 on my desktop and Office365 as the work environment as stated above. The only Office 2013 components are SkyDrivePro (which used to work fine without these cache issues) and Lync (just installed via Office365 as instructed by the Office365 site to upgrade the Lync2010 I used to have which worked fine).