FRM-92100 received when approving PO over users limits

Hi

When a user submits a PO for approval and the PO is over their approval limit they are receiving the following error message: 'FRM-92100 Your connection to the Server was interrupted. This may be the result of a network error, or a failure on the serveri. You will need to reestablish your session.'

if the PO is submitted for an amount that is within the users approval limit the error message is not received.

Any ideas on what is causing this issue. It only occurs for a couple of users.

Thanks

Catherine