Excel prevents XP Pro laptop going on standby
 

I use a laptop at work and save all my files on a network drive. I usually
have 30-50 windows open at one time. Instead of restarting the computer each
day when I undock and take the computer home I prefer to have the computer go
on standby. All other applications cooperate but Excel frequently prevents
the laptop from going on standby with a message saying a file in excel is
open on the network. Previously I could avoid that message by waiting a
minute or 2 between undocking and closing the machine, which drives the
request for standby, but recently it never allows standby. Every other app
including other office apps allow netowrk files to be open when the machine
goes on standby. Anyone else seen this and any work around known??