I defragmented my OS partition while in safe mode, then restarted and ran in normal mode.
I analyzed the partition again and the amount of defragmented files shown in the disk map differed from the "Analysis results" text (a couple of "dots" on the disk map means more than one 5.8 kb file on a 110 GB partition).
Ran another defragment and I guess the drive map was showing the correct status of my partition because the defrag lasted for at least half an hour. Also, under the "Current state" data, a lot of files were shown that they were defragmented.
Windows Vista Business SP1 x86