Two programs doing shadow copies at once (XP)

I have Carbonite installed on my computer (XP Pro) and just tried to install Norton Ghost 14 as well, to do a second backup to an external hard drive.

I got a few errors that said that Norton Ghost can't run while the computer is on (even though it normally can), which I gathered from the Norton Ghost troubleshooting materials means that its shadow copy service isn't running properly. I have my Norton Ghost backup set to use "full VSS" (Volume Shadow Service).

I'm wondering if you think this could be caused by the fact that both Carbonite and Ghost rely on volume shadow copy. Can two programs use this service at the same time?

For some reason the errors went away and both are running simultaneously, but I wonder if I could be getting corrupted backups since it's not clear why it suddenly started working.

Any thoughts would be appreciated!