XP Backup - All Network Devices Grayed Out

I have been running XP Backup for several years. It has been backing up My
Documents from several XP and Vista boxes on my network. I did a Full backup
and then Incremental backups each night. Every few months I redo the Full
backup and restart the process.

This week I added a new box to the network, went to XP backup to change
folders that were being backed up. Well, much to my surprise backup could
not longer see any of the devices on the network. All network computers are
grayed out and you cannot even open them to see the drives, folders, etc.

All of the folders to be backed up are shared and can be seen for the system
running backup.

I have not been able to find any solutions to this problem. Help.