%u not being expanded in logon path

[Andreas]

I just found out that with samba-3.0.8 (don't know about other
versions) %u is not expanded in the logon path parameter. 
%U works fine. Is this on purpose for those cases where %U is
different from %u?
%u is also used in the 4.1 example from Chapter 4 in the HOWTO.