Vista - "Access denied" error when doing user profile offline sync

We are using Vista in our company, everyone's home folder (h: drive) is having offline sync enabled on it and hence my home folder will be copied to the computer that I logged in with my account. This is not a big issue for me as I understood this is what supposed to be happening.

But I just got a wierd problem of Vista offline sync:
One day I logged in to an user's machine to help him fix a problem and I logged off after the job done. After a few days I got an email from that user with attached a screenshot of some offline sync errors on his machine.
The error said my profile on his machine is generating errors below:
-Offline Files "Access Denied"
-Sync failed with Offline Files

It looks like that my profile left on his machine is still trying to do the sync even when the user is logged in with his account.
Has anyone seen this problem before?

I don't understand why this is happening as I though the offline sync of my profile (H: drive) only happens when I am logged in.

Any advice would be much appreciated.