PowerBuilder Informix active transactions

We developed the application using PowerBuilder which runs on Informix 5.01 Online as a database server. Recently, we found the problem of number of active transactions at a time. There is a strange limitation of 4 active open transaction which we cannot exceed. Is this a PowerBuilder issue ? If this is an Infromix limitation, are we able to define this number softly, using any of Informix .ini files ? Thank you in advance Vladimir Greenstein, Astea International - Tefen Labs ph. +972-4-9872519 fax +972-4-9872031