User/Instance allocation problems

We are having problems getting users configured on a system where we are trying to setup multiple instances of informix. Originally we thought this to be a shared memory problem keeping us from starting multiple instances. After contacting Tech Support (they told us to try increasing the number of users and lower the number of locks) We discovered that if we limit the number of users in each instance at 10, all three instances will come up. Stupidly we let them close the case thinking we could check the books and figure out what parameters to change to allow us to increase the users. But according to the books we have this parameter shouldn't effect shared memory. The dependenet shared memory parameters of locks, buffers, and tablespaces are all more than adequate in all three instances to handle the 30 users we are specifying for it to initialize with. However these instances will not all start. Simply comes back and says shared memory not initalized on the others after we start the first one. We can get just one up. If we drop the number of users to 10 in each instance the instances will all come online. And this is without touching any other parameters. Questions: We are unsure if somehow maybe the number of licenses we have for the system is somehow coded into the software so that we possibly can't ever have more than 30 users attach to the the informix instances. We can determine this ourselves as we don't know how many licenses are currently approved. Does informix do some extra allocation not included in the shared memory total needed in the parameters initialization in tbmonitor that would cause there to be a problem that we can't see. Are there any Unix shared memory configuration parameters that could be affecting things. Any help would be greatly appreciated as we really don't see the point in keeping three instances online that can only accept 10 users on each. That's barely enough for the informix daemons and page cleaners. If anyone can help we would gladly send the tbconfigs for review. system is a harris nighthawk running harris unix cx/sx and Informix Online Secure 5.00 UD6. J. Brown email: brownjd@hqamc.safb.af.mil