VSS crashes SBS 2008 when backup runs

I have a HP ML350 server that has SBS 2008 Premium installed on it. I have had issues from day one. I have cleared up most of them except one.

Every night the server reboots. I narrowed it down to rebooting when the server backup runs.(using the windows backup that was included) I then disabled VSS and it does not crash anymore.

I only know alittle about VSS but I believe during the backup it is used for backing up open files and involved with Exchange during backup.

Has anyone seen this before? Or have any ideas?

Thanks.