non exclusive access

Has any one else run across this problem? If I run something like the following set lock mode to wait;begin work; lock table table1 in exclusive mode; alter table table1 or create trigger on table1 or create index on table1 commit work; I get: 242: Could not open database table (informix.table1). 106: ISAM error: non-exclusive access. So it gets to the alter table statement, it has to have run the lock table statement, and yet I don't have exclusive access!! Informix says there is no bug because they cannot recreate the problem in their sterile single user environment. Is there a work around (short of going to quiescent) thanks By the way this is HP-UX 10.2 online 7.22