System Backup Fails

I'm currently running Vista Home Premium with an Ultimate upgrade on it's way. I too am having the same problem with my system backups (backup failed) but there is one major difference between what others have posted and my problem: I do not use McAfee, I use the new Vista compatible Zone Suites. My error message is slightly different but I have the same results, not being able to run a successful backup. I'm curious, could residual McAfee programs (that were installed by Acer when I purchased my PC) still reside on my PC that might be causing this problem? Or, could the problem be with firewalls in general? I've attached a copy of the error message I get when backup fails.

Thank you for any help.

OK. Thanks anyway guys. I followed-up on this further, contacting my firewall guys (Zone) and discovered that it was in the ZA and ZS settings. I turned off the Spyware and ran the backup successfully. Didn't have to turn off the Anti-virus. I talked with the Zone tech and he recreated the same problem and discovered that once the backup ran successfully to completion, there wasn't any further need to turn-off the spyware (ZS) or anti-virus (ZA). Appears that once the backup has run to completion, all is well in the backup and fireware world!

PS There were no residual McAfee program files on my PC. I double checked and ran the Windows Install Clean Up Utility, looked at the program files, registry, etc. Nothing there (of McAfee) to indicate that could have been the problem.