squid v1.1b16 always returning ICP_MISS to siblings?

Whilst perusing "access.log" today I noticed that squid wasn't replying to
siblings requests even though the requested object was my local cache (and
indeed local clients were being returned the object from the cache).

Early this evening I noticed that one neighbour, who is also running
v1.1b16, was returning ICP_MISS to me 100% of the time. (Oh, oh - I just
noticed another neighbour has upgraded to v1.1b16 and the average ICP_MISS
rate has risen to 96%)

Has anybody else noticed this behaviour?

Regards,

Gordon.

--
Gordon Smith, Manager              |         Gordon.Smith@UNE.Edu.AU
Network and Systems Group          |          'phone: +61 67 73 2325
Information Technology Services    |             fax: +61 67 73 3272
University of New England, Armidale, New South Wales, Australia 2351