Ldap user creation failing

Attempting to authenticate and create users through LDAP. When a user attempts to connect a system error is generated -
error: Can’t call method “as_string” on an undefined value at
/opt/rt3/local/lib/RT/User_Local.pm line 88.

Using LDAP and AutoCreateFromExternalUserInfo overlay. System is RT 3.4.4 running on Fedora C4. Has anyone seen this error?

Yahoo! Shopping
Find Great Deals on Holiday Gifts at Yahoo! Shopping