Cannot connect to Online

Hello out there, since 4 weeks, there's a very strange behaviour with INFORMIX Online 7.13.UC3 on HP-UX 10.01. From time to time it happens, that no new user can establish a connection to Online (the process hangs, until online shutdown). Users currently logged in can continue their work without any problems. But when a currently logged in user closes the connection and tries to reestablish it, this user also hangs. All I can do is a "onmode -ky; oninit" to reboot online. After this everything is working fine again for a while. I've configured 2 connection methods: NETTYPE ipcshm,1,200,CPU NETTYPE soctcp,1,30,NET I've discovered that the above described problem only occurs on ipcshm-connection. If I change INFORMIXSERVER to the tcp/ip-connection, I can connect to Online. So I think there must be a problem with the shared memory. The "onstat -g seg" gives the following: INFORMIX-OnLine Version 7.13.UC3 -- On-Line -- Up 09:18:59 -- 526000 Kbytes Segment Summary: (resident segments are locked) id key addr size ovhd class blkused blkfree 520 1381517313 c0cb0000 473088000 8072 R 57746 4 265 1381517314 dcfdc000 65536000 1604 V 1842 6158 29 1381517315 ebf00000 2154496 640 M 260 3 There are no error messages in the INFORMIX or system log file! I don't have any ideas where to search for an error. The system is running now for more than 2 years. There was no INFORMIX update! The problem occurs the first time 4 weeks ago. On the machine runs a third party product which uses Online. Is it possible, that this application crashes the shared memory area of Online? Until now I believed, that this is not possible, but in the last 4 weeks there were several updates of this software. Ofcourse the vendor denies, that our problems could be caused by his software. Can anybody give me a hint, what's going on here? Any hints are welcome. Thanks in advance... Very desperatly Dirk Scheer Stadtverwaltung Muelheim an der Ruhr Ruhrstr. 32 45468 Muelheim an der Ruhr Tel 0208/455 1006 Fax 0208/455 58 1006 eMail dirk.scheer@stadt-mh.de