High Memory Usage Issue

We are developing a thick client windows application using .Net2.0 framework. Our application uses the enterprise library Jan2006 version and UIPAB 2.0.

We are facing a high memory usage issue (approximately 125MB for a time period of 5mins) while running this application. If we continue on the same scale of usage, it throws an error creating window handle exception. Whereas, when we minimize the application it consumes only 15-20MB of memory. When we maximize the application, gradually the memory usage increases during the navigation. On minimization all the memory is relinquished again.

Is there any garbage collection process followed during the minimizing the application.

If so, can it be implemented dynamically in our application?