"Funny" crash on 7.31

We've had two of them this week, both under relativly high load (generating indexes or running update statistics on large tables). I've mailed these (and the stack trace) to Informix, but decided to ask here just in case someone had "been there, done that": (Informix Dynamic Server Version 7.31.UC2 on HP-UX B.10.20) Crash 1: (During create index) 21:45:53 Checkpoint Completed: duration was 3 seconds. 21:46:35 (2) parameter error 21:46:35 Assert Failed: unxdmnbe.c, line 595, thread 10, errno=0, buffer insertion failed. 21:46:35 Informix Dynamic Server Version 7.31.UC2 21:46:35 Who: Session(2, informix@, 0, 0) Thread(10, ipcstrpoll, 0, 1) File: neterrb.c Line: 658 21:46:35 stack trace for pid 14330 written to /tmp/af.3f2761b 21:46:46 See Also: /tmp/af.3f2761b 21:46:46 neterrb.c, line 658, thread 10, proc id 14330, unxdmnbe.c, line 595, thread 10, errno=0, buffer inserti. 21:46:46 PANIC: Attempting to bring system down Crash 2: (During dostats (update statistics): 20:02:18 Checkpoint Completed: duration was 3 seconds. 20:47:45 Checkpoint Completed: duration was 0 seconds. 20:49:44 (2) parameter error 20:49:44 Assert Failed: unxdmnbe.c, line 595, thread 10, errno=0, buffer insertion failed. 20:49:44 Informix Dynamic Server Version 7.31.UC2 20:49:44 Who: Session(2, informix@, 0, 0) Thread(10, ipcstrpoll, 0, 1) File: neterrb.c Line: 658 20:49:44 stack trace for pid 29042 written to /tmp/af.3f2ba48 20:49:55 See Also: /tmp/af.3f2ba48 20:49:55 neterrb.c, line 658, thread 10, proc id 29042, unxdmnbe.c, line 595, thread 10, errno=0, buffer insertion failed.. 20:49:55 PANIC: Attempting to bring system down Thomas