Can't seem to change displayName via LDAP

I am trying to keep ActiveDirectory people info in sync with our corporate database and so I am using the LDAP interface to ActiveDirectory. When I try to change the displayName attribute I get no error back from ActiveDirectory to indicate a problem, but the displayName doesn't change (I can successfully change the value of other attributes). To make sure something else wasn't going on, I then went and deliberately misspelled the attribute name and got an error back from ActiveDirectory -- so at least I know that I was talking.

My code is Java/JNDI -- in our environment, Java is the only available language since I need to talk to the corporate DB as well (i.e., using .NET is not an option). Also, we use Exchange if that makes any difference with respect to modifying the displayName attribute of the user object.

Any ideas why the value won't change and why ActiveDirectory is not returning any error at all?

Thank,

Rob Tanner
Linfield College