"I tried to register first as sassy but it said that name was already in use.So I went with budd it said that was in use,but i tried using it anyways.Then I get a confermation for sassy.That's the one I really want to use"
The only way the user would get that error is that you had modified existing code (besides that the name was really in use, but that is not the case here). So, yes, it must be from a MOD (either faulty MOD code or faulty MOD installation).
Is it possible that the user may have in fact tried to register twice with the same name?
I have an occassional problem with users double-clicking on the email registration confirmation link, the first click confirms the registration, and the second generates a "not found" error because by that time they are already fully registered. Could it be something like that?
--Jördan It's a wasted day if you don't spend at least part of it flying upside down.