Overlay icons not working

Greetings,

Mozy's status icons are not visible. This is usually a problem from another application. The problem seems to be this registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\explorer\ShellIconOverlayIdentifiers

There are three subkeys that I think are causing the problem: overlayexcluded, overlaypending, and overlayprotected. It looks like when I removed a previous Norton product, the entries in the Registry were not removed. Is it safe to delete these keys?

Thanks,
Shane.