Let's isolate the hanging issue if it happens on the DB or Application. In this way we can concentrate more on where it happens.
1. When it hangs again, don't kill it yet and go to SS Management Studio then execute a simple select statement on the table of the last SQL that was executed as per the sql profiler. If you can execute successfully with the resultset while the PB application is running/hanging then it's safe to say it not due to table lock.
2. Check if there are triggers firing
3. Try to turn on the PB trace. e.g dbms= Trace <value>