QuickBooks Backup Blocked

NIS 2012 / XP SP3

 

One of the updates during the past week has caused backing up QuickBooks to quit working.  I get an error message "The drive you specified is not valid".  This happens regardless of what drive I choose to backup to - all drives are otherwise accessable and working fine.

 

Disabling Smart Firewall and Antivirus Auto-Protect does not help.  If I boot in safe mode it does work.

 

I have restored my drive with a one week old Ghost image and all is fine until I run Live Update, then this problem appears.

 

I have done a clean install of NIS and XP and all is fine until I run Live Update.