ISS 6.0 & Active Directory

I'm wondering if IIS 6.0 stores the AD information? I'm using IIS 6.0 and
Win 2003 Active Directory in Native Mode.

We're currently working on a web application that references AD to get the
username associated with the login. The system does the lookup correctly
and gets the name from Active Directory, but for some reason when the names
are changed the application never gets the name change. Is this information
somehow cached in the server or IIS?