Trasparent Proxy + ERR_C0NNECT_FAIL!!!

If you use trasprent proxy Please read this message:

I using squid (1.21) in trasparent proxy since 6 month
in a linux machine with 6Gb of HD and 128MB of Ram.But my user
report me a very NOISE problem. Often squid report this error:

host down OR operation alredy in progess.

After some reload in the browse , squid show
the page correctly.

I've check the log it reports: ERR_C0NNECT_FAIL. I've check the
site while squid write this error in the log, and the site is
up and work! I've try to disable squid and the page show
correctly!

Anyone have this problem?
Any idea to solve this very noise problem?

Squid cfg:

http_port 80
source_ping off
cache_mem 48
cache_swap 5000
maximum_object_size 4096
ipcache_size 1024
log_fqdn on
dns_children 10
connect_timeout 120
read_timeout 15
client_lifetime 200
httpd_accel virtual 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on
Received on Sat Apr 04 1998 - 10:31:45 MST