Some invisible files are missing

[Rebel]

Then why have my backups always been the same size as the source before? I never had any reason to question it since the sizes always matched.

Only after upgrading from Leopard to SL and getting my computer back from Apple do the sizes no longer match.

I see where SD says it skips temporary and system specific files, but I figured those must be very tiny and insignificant since they didn't affect the size of the backup enough that I noticed it. Now there's nearly a 5 GB difference. Anything specifically related to SL? I switched to it after receiving this computer, right before sending it to Apple. I've been using Leopard the last 2 years or so, and had no issues with SD.