Users need to have Full Control permissions on the folder in which the profiles reside.
That is the first thing I would check.
To see where the profiles are being stored:
-Open Active Directory Users and Computers.
-Click the domain and the OU where the user account resides.
-Right-click the user account for which to set a roaming profile, and then click Properties.
-Click the Profile tab, and look for the path information in Profile path.