samba - May 2002 - Read-only users opening files in DENY_DOS vs DENY_NONE mode

Occasionally, when read-only users (via Unix permissions) open an Excel
file, the file is opened with a Deny Mode of DENY_DOS, instead of (what
I take should happen) DENY_NONE mode.  Of course, this then prevents my
read/write users (again, Unix permissions) from updating the file, and
then I get a call asking to track the read-only user down.

We're running Samba 2.2.4 now, but this happened on 2.2.3a (and possibly
other older versions as well).

TIA,

Ken McCord