Forms hangs

Using forms11gr2 on linux 64bit

32 bit win xp workstations

We are in UAT, converting our first app from 6i to 11gr2. We get hangs every hour or so. nothing is showing on the jvm console, no errors.
Just hangs after selecting a field. clicking a button, or running a report....we see the status bar moving for 1 sec then hangs. sometimes we do not see the status bar movings.
Mostly happens while in forms (sometimes in reports)
what error logs could help me debug it on the server.
Server as 32gb of ram. 2 users testing the server, so its not a load issue.