Time Machine Keeps RE-backing up everything

[bombtrack]

I have a Time Capsule as my Time Machine backup, which backs up my MBP and the external drive I use to hold all my files. The initial backup was roughly 400GB--325GB of which is iTunes related.

The initial backup--which I have done numerous times now--went fine. However, the next time I have the external drive connected, when Time Machine starts up to do its hourly incremental backup--it shows XXGB of 365GB ... so it is trying to re-backup my entire iTunes library. Anybody have this problem and find a solution?

 

[JediMeister]

What version of Mac OS X Leopard do you have on the MacBook Pro and have you checked if there are any firmware updates for the Time Capsule?

 

[bombtrack]

I'm running 10.5.6 on the early 2008 MBP. The Time Capsule has the most current firmware available.

 

[isx]

Do you use VMware or Parallels If so, if you make any changes in the guest OS it will backup the entire install as it is one file. Add it to the folder your guest OS is in, if you have one.

 

[bombtrack]

Could the Genius be causing this?

I have boot camp installed and am running Vista on the other partition. However, after I installed that, I deleted the Time Machine files completely (off the TC) and re-did the backups from scratch. Also, the big chunk of GB that TM starts backing up is on an external drive. Surely making a change to the Vista partition would not cause the external drive to redo the complete backup would it??

My current theory is that, perhaps, when iTunes scans my library for Genius info, it is somehow causing all of the 70,000 or so music files I have to change enough for TM to think it needs to back them all up ... anyone care to comment if this makes sense??