Segmentation Violation (bad memory pointer)

We are running Online DS 7.22 on SCO Unix 5.04 (release supp c). Has anyone seen the folowing problem before? Thanks, Lutz Wiggershaus 13:45:50 Checkpoint Completed: duration was 0 seconds. 13:50:53 Checkpoint Completed: duration was 0 seconds. 13:55:56 Checkpoint Completed: duration was 0 seconds. 13:57:34 Assert Failed: Condition Failed (Bad memory pointer 0xffffffed), In (mt_shm_free) 13:57:34 Who: Session(397, hel2@bdv50001, 23941, 0) Thread(425, sqlexec, 0, 1) 13:57:34 Action: Please notify Informix Technical Support. 13:57:34 See Also: /tmp/af.1a9213d, shmem.1a9213d.0 13:58:40 Assert Failed: Internal Error - Segmentation Violation 13:58:40 Who: Session(397, hel2@bdv50001, 23941, 382093896) Thread(425, sqlexec, 16c47e2c, 1) 13:58:40 Results: OnLine must abort 13:58:40 Action: Reinitialize shared memory 13:58:40 See Also: /tmp/af.1a9213d, shmem.1a9213d.1 13:59:50 rsinit.c, line 9934, thread 425, proc id 517, Segmentation Violation. 13:59:50 PANIC: Attempting to bring system down