[Samba] %u not expanded for log name

[Bryan Vicknair]

I am looking to have my log files named by the user's unix username as
it exists on the samba server, not the username that the client
requests.

Logging in from a Windows 7 client with username Bryan.  I have mapped
Bryan to a unix username bry.  When I use %U in my log filenames, it
expands to "bryan".  When I use %u, it doesn't expand, it appears in
the log filename as a literal "%u"

smb.cnf:
log file = /var/log/samba/%u-%m.log

/etc/smbusers:
bry = Bryan

Log filename == %u-438-bv.log

Samba 3.4.7 running on Ubuntu 10.04