bcheck - perm help!

ATTN: Alan Popiel (who also runs this old stuff!) and anyone else who remembers 2.10! We run Informix SQL 2.10.03G (yes it is old, but it usually works, and Uncle provides no monies for new....) The owner of this database runs this SQL statement from isql menu, Query, New, and gets this message: >>>>>>>> check table mytable BCHECK C-ISAM B-tree Checker version 1.07 Copyright (C) 1981-1988 Informix Software, Inc. C-ISAM File: tda.dbs/tdafile102 ERROR: cannot open C-ISAM file <<<<<<<<<< ORdinary table queries on this table work ok, adds, updates etc. Perms on the db.dbs are 770, owner is db owner, group is informix; All files in db.dbs/* are 660, owner is db-owner, group is informix; Informix is still in the password file, and the only member of the group. This unix setup usually works for us, and has always allowed our databases, (including this one), to work before. The user can run queries, just not check or repair table. No new software etc has been added, or changes made. When I change perms to 777 on db.dbs and 666 on db.dbs/* she can run the query. I checked perms on sqlexec, bcheck and isql and they appear the same as other systems running this same version: -rwxr-xr-x 1 informix informix 93886 Oct 24 1990 /usr/informix/bin/bcheck -rwxr-xr-x 5 informix informix 453527 Oct 24 1990 /usr/informix/bin/isql -rwsr-sr-x 1 root informix 262498 Oct 24 1990 /usr/informix/lib/sqlexec are these right? Where else should I check? Thanks. Ann