This is pretty frustrating as I do everything humanly possibly to exclude all the obvious things from time machine (downloads, cache, iOS apps) as well as the notorious problem areas (virtual machine). About 3 weeks ago I upgraded to a new 500GB hard drive, transferred everything from Time Machine and everything took place OK. Today I go ahead to do a backup and after preparing the 500,000 files it told me that it was about to do a 33GB backup! THIRTY THREE GIGS!!!! How is this possible? The excluded folders are still there--obviously I have not changed around 33GB worth of stuff on my computer in 3 weeks. I have BackupLoup to check what gets changed but I am not about to eat up 33GB on the external hard drive just so I can figure out what the hell it is that Time Machine wanted to back up when I can't erase that backup! Can anyone think of any reason why this would be happening?