I am using SQL 2005 and my issue is SQL stop communication when backup is running. (i am ruuning backup at 6 PM Sql server stop communicating at 6 and never cameback until i restart the machine)
And by "stop communicat(ing)" you mean that client connections do not respond?
How many databases are you backing up? How large are they? Are they backing up to a local disk drive, or over a network or SAN? Is the maintenance plan only doing backups, or does it also do index maintenance?