Check that the hover color, fore color and background color values are all the same. Since the hover color property doesn't apply to db's older than 2013 (I think) you might end up with a combination of colors that cause flickering. If they are the same, try removing any themes that might be causing it. This assumes you don't have any Mouse Move event running since you mentioned that it happens for all forms. I presume this only happens when you've opened the db from 2010 in your newer version.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.