Upgrade or just re-license?

Hi All, I've just joined a compnay who have the following products: V4 STD Engine Runtime (D32) V4 STD Engine (D16) V4 RDS Runtime (D32) V4 RDS Devsys (D16) V4 SQL Runtime (D32) V4 SQL Devsys (D16) All this is running on an RS6000 running AIX 3.1 and no Informix Assurance payments have been made since the software was bought some 6 or 7 years ago. I will be upgrading AIX to 4.2 and need to re-license Informix. As I will be the only developer there is no need for 16 user licenses for the products, 1 would suffice. To cut down on costs I was proposing to just re-license our Informix releases to run on AIX 4.1 and stick with the versions we have. There is no real need for us to move to a newer release as the software that has been developed in-house before my arrival does the job. My concern would be support for V4. If I do re-license and stay with V4, am I going to hit problems in the months/years ahead? Another reason for staying with V4 for the time being is that once I get familiar with the software I was thinking of a switch to a client/server proposition involving an NT boix running SQL Server and writing VB stuff for running on PC's and hooking up to the database with ODBC. But that is another can of worms :-) Feel free to comment on this if you wish. Any comments/views most appreciated. Cheers, Ian.