Help: Upgrade to 7.11

Hello All! I work with an application that is written in 4gl for OnLine. The operating environment is HP-UX 9.04. The application (.4ge executables) run on a client HP 9000 and the database is on a different HP 9000 server. The UI is Informix forms. We recently upgraded from 7.10UC2 to 7.11UC1X2. The procedure we followed was: STEP 1) Bring up the engine in 7.11 mode and test the application. STEP 2) Use onmode -b 7.10 to revert back to 7.10 and test the application. STEP 3) Go to 7.11 and stay there (and pray). STEP 1 worked great. STEP 2 was meant to give ourselves a warm feeling about being able to go back to 7.10 if 7.11 gives rise to some unforeseen problems. This is where the problem occurred: When the engine came back up in 7.10 mode, the applications, through forms, could execute selects, inserts and updates without a problem. As soon as a delete was attempted, the user got an SQL error message, "SQL Err. -25580 System error occurred in network function." On the server, the engine crashed and the log read - 22:37:49 Assert Failed: Internal Error - Segmentation Violation 22:37:49 Who: Session(11, "userid@client", 17572, 9) Thread(39, sqlexec, c04d2874, 1) 22:37:49 Results: OnLine must abort 22:37:49 Action: Reinitialize shared memory 22:37:49 See Also: /tmp/af.21b962c1 22:37:49 rsdebug.c, line 3557, thread 39, proc id 9536, Segmentation Violation. 22:37:49 PANIC: Attempting to bring system down We could reproduce this at will. Has anyone else seen this behavior? Should I lie awake at night, fearing user wrath when I tell them that, after all, we can not revert back to 7.10 in 30 minutes? Also, can anyone suggest how we can go back to 7.10 if the need arises? If we bring up the engine in 7.10, run dbexport, drop and recreate the database and then run dbimport, will that be clean? TIA - Atul.