Help with AIX and Informix 7.12

Folks, forgive me; I'm a little new at this... I'm running Informix 7.12.UC1, on AIX 4.1.4. I've just installed this, and the friendly folks at Informix Tech Support assure me that I've got the right version for my operating system. Problem is that every 15 minutes or so, my 4GL applications stop talking to my engine. I'm running the 6.xx (I can't exactly remember the version number) version of the tools; those are also just recently ordered and installed. I'm using shared memory connections, and I've got a 2 CPU machine configured as a multiple CPU machine, with 2 CPU VP's. I've not got any other VP's set up, other than the AIO VP's that AIX automatically sets up for me (and boy, have I got a lot of them...). If anyone has been able to make anything that looks like this work for them, please let me know. I'm at the end of my rope here. Thanks in advance... -- Dan Michaelis