incomplete loads

I am running Squid 2.2.STABLE4 with hno.19991019.snapshot patches on Linux 2.0.36
and I am rather frequently seeing files being incompletely loaded - ie. HTML
pages breaking of in mid-text or images showing only the top part. A simple
browser reload only shows the same incomplete info again, but shift/reload
in most cases gets the complete info. My log files do not seem to show anything
out of the ordinary. Here's a typical sequence grepped from access.log for a
page first loaded incompletely, a reload without shift showing the same partial
result again, and a shift/reload finally retrieving the complete page:

940509416.770 41246 HeartOfGold.sema.de TCP_MISS/200 27312 GET http://news.cis.dfn.de/de/hierarchies.html - FIRST_PARENT_MISS/www-cache.xlink.net text/html
940510352.620 12242 HeartOfGold.sema.de TCP_MISS/304 239 GET http://news.cis.dfn.de/de/hierarchies.html - PARENT_HIT/www-cache.xlink.net -
940511646.728 133775 HeartOfGold.sema.de TCP_MISS/200 27203 GET http://news.cis.dfn.de/de/hierarchies.html - PARENT_HIT/www-cache.xlink.net text/html

The portion of cache.log around that time shows:

1999/10/21 14:17:17| Detected DEAD Parent: www-cache.xlink.net/3128/3130
1999/10/21 14:17:18| Detected REVIVED Parent: www-cache.xlink.net/3128/3130
1999/10/21 14:28:01| TCP connection to www-cache.xlink.net/3128 failed
1999/10/21 14:39:31| Detected DEAD Parent: www-cache.xlink.net/3128/3130
1999/10/21 14:39:32| Detected REVIVED Parent: www-cache.xlink.net/3128/3130
1999/10/21 14:52:20| clientReadRequest: FD 86 Invalid Request
1999/10/21 14:53:33| Detected DEAD Parent: www-cache.xlink.net/3128/3130
1999/10/21 14:53:34| Detected REVIVED Parent: www-cache.xlink.net/3128/3130

Our (single) parent is running Squid 2.2.STABLE3.

Any hints on where to look for further tracking this down?

-- 
Tilman Schmidt          E-Mail: Tilman.Schmidt@sema.de (office)
Sema Group Koeln, Germany       tilman@schmidt.bn.uunet.de (private)