Problem: Two identical folders are reported as not being identical

Solution: It took awhile to run this down but the problem is not with OneOnOne but with XP. XP puts an invisible file in each folder called thumbs.db. It will be in each folder and it will always be different in each folder so OneOnOne will always say that the folders are different but if it only finds thumbs.db in each then it is OK they are identical.

Alternately you can remove thumbs.db by following instructions at
http://www.annoyances.org/exec/show/article03-203
and
http://www.annoyances.org/exec/show/article03-204