Online crashing while doing backup

Hi We are running Informix Online Version 7.11 UC1. After backup is done, Infomix engine dies occasionally. Any ideas? The follwing is obtained from "online.log" ----------------------------------------------- 08:42:29 Archive on rootdbs, maisdbs Completed. 08:42:31 Checkpoint Completed: duration was 0 seconds. 08:43:43 Assert Failed: Internal Error - Segmentation Violation 08:43:43 Who: Session(299, informix@fwmais2, 19434, -1) Thread(329, ontape, 40015d34, 1) 08:43:43 Results: OnLine must abort 08:43:43 Action: Reinitialize shared memory 08:43:43 See Also: /tmp/af.ce88c0, shmem.ce88c0.0 08:44:03 rsdebug.c, line 3650, thread 329, proc id 12326, SegmentationViolatio n. 08:44:03 PANIC: Attempting to bring system down Fri Apr 16 09:27:05 1999 09:27:05 DR: DRAUTO is 0 (Off) 09:27:05 *** _aiostat() SUCCESS: /usr/informix/dbs/rootdbs 09:27:05 *** _aioinit(): Pid = 11804 09:27:05 *** _aiostat() SUCCESS: /usr/informix/dbs/maisdbs1Log is poingint to file which contain following information. --------------------------------------- The contents of the file in "/tmp/af.ce88c0" is: ------------------------------- 16:02:36 16:02:36 Assert Failed: WARNING! Chunk 2 is being taken OFFLINE. 16:02:36 Who: Thread(6, main_loop(), 4000a010, 1) 16:02:36 Results: DBspace maisdbs1 is disabled. 16:02:36 Action: Restore DBspace maisdbs1 16:02:36 See Also: /tmp/af.15600 16:02:36 --------------------------------------- Thank you Sukumar