When load balancing Oracle e-Business applications with the ACE we have clients in one remote location that cannot pull up anything that requires Oracle forms. All other locations work fine, and if the problematic clients connect directly to the server instead of through the ACE they also work.
I have not found any differences in the way this remote site connects that can explain this behavior, and have check the MTU on connections from this site. A sniffer capture shows a MTU of 1300 being negotiated.
Finally, these clients connect and work fine until they try to pull up the forms.