Multiple instances of postgres.exe, Geoserver hangs

Hi!

We have a problem with Geoserver, PostGIS and MapBuilder.

Our map displays fine, but we noticed a lot of instances of postgres.exe in the task manager, simultaneously, mapbuilder fails to refresh some layers, let's say street layer, that were showing, 20 or 30 seconds later you pan the map and then street layer are not anymore shown.

We're not sure what causes the problem.

Is Geoserver requesting too many connections? (we test it from only one client and still dozens of postgres.exe instances)?

Is Postgres.exe refusing more connections as a result of the many instances?

Could it be a driver / connector problem?

Thanks !