I found this:
Print additional debugging information for the mount. Note that
this parameter must be specified before the -o. For example:
mount -t cifs //server/share /mnt --verbose -o user=username
The primary mechanism for making configuration changes and for reading
debug information for the cifs vfs is via the Linux /proc filesystem.
In the directory /proc/fs/cifs are various configuration files and
pseudo files which can display debug information. There are additional
startup options such as maximum buffer size and number of buffers which
only may be set when the kernel cifs vfs (cifs.ko module) is loaded.
These can be seen by running the modinfo utility against the file
cifs.ko which will list the options that may be passed to cifs during
module installation (device driver load). For more information see the
kernel file fs/cifs/README.
I might try some of this when I get home...................