ontape -p produce "Segmentation Fault" (IDS9.40UC5 on Solaris)

We installed IDS9.40UC5 and converted the database from IDS9.30UC5. The conversion was successful. It only took about 50 seconds to finish the conversion so it's obvious that not much update has taken place during conversion. After the system is online with IDS9.40UC5 I took a level zero archive into a disk file, which is about 80GB in size, then use "ontape -p" to restore. With exactly the same archive, the physical restore sometime works sometimes doesn't !! It always prints the chunk information, ask "Continue restore? (y/n)" then "Do you want to backup the logs?", after a few seconds, "Segmentation Fault" is displayed on the screen, ontape process has gone but "oninit -r" processes are still running. When I use "ipcs" command to monitor it, new shared memory segments are created after "Segmentation Fault" has occurred. The "Physical restore ... started" message has Not appeared in the engine log. No core dump is produced in the directory where I ran "ontape -p". Sometimes it does work and everything is normal. Note again that on the same archive sometimes it works sometimes it doesn't! I have got the latest Solaris recommented patch cluster installed by the Unix admin but the problem still persist. Also as suggested by IBM support I have tried run the "installserver" and "RUN_AS_ROOT.server" scripts again, it didn't help. Any ideas? Your help is appreciated! OS version is Solaris 5.8: misaccshm@osun9071:/mis/a00/users/informix/upgrade2004/archecker)uname -a SunOS osun9071 5.8 Generic_117350-21 sun4u sparc SUNW,Ultra-80 Screen cut and paste: Continue restore? (y/n)y Do you want to back up the logs? (y/n)n Segmentation Fault Regards, Carl Wu