Active Directory Users and Computers Find

We have a mixture of 40 Win 2003/2008 DC's in our Domain and when trying to find a user in ADUC, some of the DC's are returning strange results.  Previously if i searched for a user account using find in ADUC by entering the firstname and surname, the result would return the one user i had searched for.  Now some of our DC's are returning multiple results as if it is searching the first and suname individually.  Example, searching John Doe would usually return the user John Doe, but on some DC's it now returns every user called John or any user with John somewhere in the name like Johnson for example.  If i do an LDAP query using custom search this returns the one user i am searching for correctly.  I know this may not seem like a major problem but i have a lot of admins who use the find feature and dont know how to do an LDAP query so need to resolve this.