Informix parameters setup ...

Hi We have a Powerbuilder 4.0 with Informix 7.12 running on an NT SERVER. The clients are connected on a TCP-IP network to the Server. The problem we are facing is that if the Client connection is lost due to various reasons (Rebooting of the client, Application Error, GPF etc), the server does not allow new connections for quite sometime, any connections attempted after the failure were timed out with SQL ERROR -932 (This happens both with Powerbuilder as well as I-Net Login window). We initially suspected that it could be a network problem, but found that other applications like e-mail that uses netwok extensively are working fine, Could this be due to Improper setup of the Informix Database?. We would like to know what kind of parameters should be looked and what kind of values these should be set ? Thanks!