Hi,
Have you tried the following?
IUser user = request.getUser();
String uID = user.getUniqueID();
IUserMaint modUser = null;
IUserFactory ufact = UMFactory.getUserFactory();
modUser= ufact.getMutableUser(request.getUser().getUniqueID());
The getMutableUser method expects a user id , not a name.
Best Regards,
Tal