When using the newest version of the Network theme, several buttons in the admin area are being improperly styled. The theme seems to be taking them over. This happens in multiple areas within the site admin panel. Please see screenshot of one of those areas & the buttons involved.
When disabling the Network theme and reverting to the default WP theme this issue resolves itself.
I'm running the latest WordPress on a Multi-User setup. Win7 64bit - IE9. This happens whether in compatibility mode or not.