problems with prefer_direct Version 2.2.STABLE5-hno.20000202

I have just upgraded some 2.2stable4 + various patches to Version
2.2.STABLE5-hno.20000202.
We have a 2-tier structure, with client access boxes talking direct to a
second level that go to the internet. We want the client access level to
prefer the parents. Under 2.2S4, prefer_direct on mean that our stats
showed anly a few dozen out of 100k requests went direct. Now we are
seeing about 25% going direct. Doing a debug 44,5 to show peer select
seems to indicate that ICP replies may not be being seen

Is this a known issue (couldn't find any references in mail list)

PS is CARP a good idea for the parent selection. We currently use ICP
and a cache_peer_domain slpit to select the peers

--
Darren Steven
Applications Specialist
Networking Tasmania
Telstra Australia
Ph.1800 813 302