ShadowProtect Desktop continuous incremental file size way too big

I am having some trouble with ShadowProtect's continuous incremental. I set it up following these directions: https://www.wilderssecurity.com/showpost.php?p=1203715&postcount=2 with 60 minutes between incrementals.

The problem I am having is that the size of the incremental backups jumps all over the place, even when my computer is idle. Some of the backups will be less than 10mb. Some will be 70-100mb, and occasionally one will be 1GB or more. My last incremental was 2.35GB and the computer had been idle the whole time.

I have already disabled Windows Vista's defrag task, and do not have any other defragger installed. The only programs running in the background are:

NOD32 4.0.437
Look n Stop 2.06p4
Clipmate
Vmware Workstation (with no vms running)


lsass.exe is constanly writing to the disk according to Process Explorer, but it's only in bursts of 500-800 bytes, so it shouldn't be building up to gigs of writes.

Any ideas?

Thanks!

 

My thought as well,,,,something auto-updating,,,,like security software or even Windows itself.

 

I should have thought of that. I have a license for Beyond Compare 3. Let me install that and see what I get.

Thanks for the idea!

EDIT -
Mounted the 2.35GB incremental and the one just before it in read only mode and had BC3 do a comparison. I got a lot of access denied errors while it was trying to do the compare. Now I'm going to copy all the incrementals, mount the copies as writable and modify permissions so BC can get into the folders. Will report back with what I find.