strange syslog messages from Squid (file_open: error)

I recently switched from version 1.0.9 to version 1.NOVM.18 of Squid. Ever
since, I am getting quite a lot of error messages of the following type in
my syslog:

Dec 1 08:29:07 proxy.sema.de squid[13155]: file_open: error opening file
 /var/squid/cache/07/0E/00001C77: (2) No such file or directory
Dec 1 08:29:07 proxy.sema.de squid[13155]: storeOpenSwapFileRead: Failed for
 'http://www.ispo.cec.be/ida/text/english/bas05.gif'
Dec 1 08:29:07 proxy.sema.de squid[13155]: file_open: error opening file
 /var/squid/cache/03/13/00001A9B: (2) No such file or directory
Dec 1 08:29:07 proxy.sema.de squid[13155]: storeOpenSwapFileRead: Failed for
 'http://www.ispo.cec.be/ida/text/english/up05.gif'

None of my users has reported any malfunctions, but that doesn't really
mean anything. Can anyone explain these messages? Is there a way to get rid
of them? I am running Squid 1.NOVM.18 with the "retry" patch (but the
messages were there before I applied it) on a SPARCstation with Solaris 2.4
and the current recommended patch cluster.

Also, I don't like those ERR_CLIENT_ABORT and ERR_NO_CLIENTS messages
cluttering my cache.log file. These aren't, in my opinion, actual error
conditions that something has to be done about, and if I want to know about
them I can always look them up in access.log. Is there a way to change this
logging behaviour?

-- 
Tilman Schmidt          E-Mail: Tilman.Schmidt@sema.de (office)
SEMA GROUP GmbH                 tilman@schmidt.bn.eunet.de (private)
Koeln, Germany