I don't have this problem, but I did find a forum thread elsewhere that had someone resolve this buy going to these 2 keys and changing the values from blank to putting a space in the fields.
\HKEY_LOCAL_MACHINE\Software\Microsoft\Windows CE Services\AutoStartOnConnect
\HKEY_LOCAL_MACHINE\Software\Microsoft\Windows CE Services\AutoStartOnDisconnect
Give it a shot, restart and see if that helps. This is on your PC of course, not the mobile device.
And here is one from a Microsoft forum post that suggests deleting a key from both of these, but it doesn't specify what exactly. Take a look and see what you think.
http://social.microsoft.com/Forums/e...-815773a20102/