samba - May 2010 - Samba 3.4.7-0.2, Windows 7, roaming profile issues

After update from 3.0 to 3.4.7 roaming profiles were not being saved
on XP.  Disabled ipv6 on our Samba server (some update must have
re-enabled it) and rebooted.  Now profiles on XP seem to be working OK
again.  

Not so for Windows 7.  This is a newly set up Windows 7 machine,
registry fixes were applied as indicated here:

  http://wiki.samba.org/index.php/Windows7

was able to join domain, and domain users can login.  However the logins
are very slow (55 seconds from start to screen stabilizing on logon). 
Of that it takes about 20 seconds to get to the "preparing the
desktop",
and the next 30 waiting for it.  Conversely, a network logon for one of
the XP machines (same account) takes only 17 seconds.

The roaming profiles are separated by Windows version, one shows up as
"Vista.V2" and the other as "WinXP".  Full path on the
server is
/u1/usr/profiles/mathog/ and then one or the other of the windows folders.


There are errors in the W7 system's application event log.  On every
domain user login there is first an error 1515:

"Windows has backed up this user profile.  Windows will automatically
try to use the backup profile the next time the user logs on"

then an error 1511 (these are logged at the same time, to the second)

"Windows cannot find the local profile and is logging you on with a
temporary profile.  Changes you make to this profile will be lost when
you log off."

The only other change to the W7 systems was using gpedit.msc to change:
computer config -> administrative templates -> system -> user profiles

change "set maximum wait time for the network" enabled and value 0. 
It
didn't speed anything up though.  Setting it back to its original
setting didn't change anything.

Profiles ARE saved back to the samba server on each logout, but they
seem not to be copied back or used on the next log in.

What am I doing wrong here?

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech