SuperDuper! post-copy action

[techno]

So I ran a Smart Update, and then immeadiately ran another one without doing anything more than continuing to surf the web and listen to music.

Here's what it told me the second time around:

Files evaluated: 940,247
Files copied: 276
Storage evaluated: 416.2GB
Storage already up to date: 410.1GB
Storage copied: 1.1GB
Elapsed time: 17 minutes, 53 seconds

(And that was with Spotlight trying to backup the mounted disk image.)

Anyone know why the logs don't add up correctly? I thought the already up-to-date files and the copied files would total up to equal the storage evaluated, but they're a few gigabytes off.

I take it that copy time is about normal? Maybe last time I did something like rename a large folder without knowing. Does that cause SuperDuper! to re-backup everything in that folder? I know the Finder can preserve aliases if one of the files or folders is renamed, but can SD just change its directory when doing a Smart Update or does it just see that a folder is there that wasn't before and back it up from scratch?

I'm running SuperDuper! 2.6.2 on a 2.0GHz MacBook with 2GB of RAM on Mac OS X 10.6.4.