Running SE 4.0 on AIX 4.3

My company has an old version of Informix SE (4.0) which was written to run under AIX 3.x. Our ex-IT manager successfully managed to move it to an RS6000 (F50) running AIX 4.2. Now we have a new RS6000 (6F1?) which only works with a minimum AIX version of 4.3. There's a LOT of reasons not to do this (and to upgrade the Informix product), but the powers that be at our company have decided to try this experiment, and if it works properly it may buy some time before spending $60k-$70k to upgrade. Disregarding whether this is a good idea or not, does anyone have any experience running an old version of Informix SE (4.0) on AIX 4.3? I'm guessing 4.2 and 4.3 are very similar, but there must be some significant difference or 4.2 would run on the new RS6000. Any help much appreciated! Joseph Dobbs Programmer/Analyst Lifeline Home Health