If you've ever come across the following error when looking at Sharepoint 2010 My Sites:

There was a problem retrieving data for this field. Updating values in this field is disabled temporarily. You can still update values in other fields.

Look no further.  This is why:

www.wictorwilen.se

However, you will need to first configure your Managed Metadata Service.  Great Instructions here:

salaudeen.blogspot.com