samba - Jun 2005 - smbfs intermittent errors: tdb_lock failed, ERRDOS 71

Hi,

I recently upgraded an older box running as a file server for a small 
company to Mandriva (Mandrake) 10.1. It's running Samba 3.0.10.1, the 
default Mandrake package.

We have a custom script that mounts a Windows share using smbfs, backs 
up specific directories, and unmounts when it's done. The problem is, 
it's not mounting reliably.

There is an entry in /etc/fstab for the share, complete with login 
credentials. Usually I can just log in as root and run:

mount /home/dubois/smb/dumas

... and it mounts and runs just fine. But sometimes it fails to mount, 
returning
> Mounting: /home/dubois/smb/dumas
> 6606: tree connect failed: ERRDOS - 71
> SMB connection failed
Other shares on other computers mount just fine--it's always this same 
remote computer, which is running Windows XP Professional.

I find in the /var/log/samba/smbmount.log this:
> [2005/06/02 03:19:50, 0] tdb/tdbutil.c:tdb_log(725)
>   tdb(/var/cache/samba/gencache.tdb): tdb_lock failed on list 16 
> ltype=0 (Bad file descriptor)
> [2005/06/02 03:19:50, 0] tdb/tdbutil.c:tdb_log(725)
>   tdb(/var/cache/samba/gencache.tdb): tdb_lock failed on list 16 
> ltype=1 (Bad file descriptor)
> [2005/06/02 03:19:50, 0] tdb/tdbutil.c:tdb_log(725)
>   tdb(/var/cache/samba/gencache.tdb): tdb_lock failed on list 48 
> ltype=0 (Bad file descriptor)
> [2005/06/02 03:19:51, 0] tdb/tdbutil.c:tdb_log(725)
>   tdb(/var/cache/samba/gencache.tdb): tdb_lock failed on list 16 
> ltype=1 (Bad file descriptor)

With the previous Linux installation, an older Red Hat install with 
somewhere around version 2.1, this share had been mounting flawlessly 
every night for the last month. Since upgrading, it seems to fail 50% of 
the time, and succeed 50% of the time. I'm using the old smb.conf and 
smbpasswd files, but otherwise all the other supporting Samba files are 
from the new installation.

Anybody have any hints, tips, fixes, or troubleshooting steps? What more 
information should I provide?

Thanks,

-- 
John Locke
"Open Source Solutions for Small Business Problems"
published by Charles River Media, June 2004
http://www.freelock.com