forms servers not balancing properly

I've got a server with one weblogic server, inside of which I have 9 Forms servers. Usually, they do a decent job of managing themselves and balancing the load across. Now, I've got 2 servers handling about 230 connections each, while the rest of them are handling 20-30. Users are getting sporadic FRM-92014 errors (A network error or server failure has occurred The request was sent to the wrong application server (not the one which created the session). The forms client has attempted to migrate the session 5 time(s) without success. You will need to restart your application).

'These FRM- errors don't start occurring until one of the forms servers gets too overloaded.

Restarting the app server tier (all processes) multiple times has failed to correct the issue. Most of the notes in can find on the internet and on oracle support talk about restarting the various servers too quickly or in the wrong order, but we've already tried slowing down the startup routines. It makes no difference.

Does anybody know why the FORMS servers would stop load balancing or how to persuade them to start again?

OS is Solaris 10 if it makes a difference.

Matt
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