What is causing this?

9-28-2004 9:27:26 am: PROXY-4.2-8

Novell Proxy encountered a fatal error: RsStateNotImplemented
callback was called for a request in state AvailableRequest

Loading Module PROXY.NLM [ OK ]

9-28-2004 9:27:28 am: PROXY-4.2-108

NMAS Proxy Authentication Services Are UP.

It is killing my Transparent Telnet sessions.
The server is running:
Upgraded from nw6 bm3.7 and had the same problem.
NW6.5 SP2, edir8732, TCP657h
BM3.8 SP2A, bm38fp3b, Craig's proxy.cfg 13
Slave S2S (using VPSLAVE still)
Telnet is to a public address
Transparent Telnet proxy is used for user based authentication to this
restricted site.
About 100 users.

This error occurs anywhere from 5 times a day to once a week.