This is a problem that I've seen in Backup for awhile now (since at least Backup 2) and haven't been able to find a solution. I downloaded Backup 3 and created a plan to backup the contents of a folder to my Windows PC via samba. Backing up the plan works perfectly. However, once the restore process reaches "Copying Files", the Windows PC crashes (the mouse doesn't even move). As a result the Finder becomes unresponsive and I have to shutdown my PowerBook by holding the power button (using force quit to relaunch it doesn't work and neither does kill -9).
It seems though that this problem is not limited to the Backup app. I see the same behavior when I attempt to copy the backup files to my Mac using either the Finder or the Terminal. In the Terminal I have to use the cp -R command since it reports the backups are not files, but directories instead.
I really would like to use my PC as a backup destination since I have about 100GB of free space there. Any suggestions are greatly appreciated.