Profiles under Windows NT 4 Server

I have NT 4Workstations with an NT 4 Server domain and latley my some of my user profiles have been changed from “username” to “username.bak” while creating a new one and loosing all the settings I had on the previous one. I log in as the admin and delete the new profile and rename the “username.bak” back to “username”.but when I login as the user it just creates and newer profile called”username.000″. what can I do to prevent this not sure if it is the server or the workstation….these profiles are not roaming.