get the page on refresh...
Please post entries from squid's access.log , for the particular request (the failing attempt, and the refresh-working-attempt)
nothing is changed in squid
Usually, as the interaction with a list works, this statement is senseless because no none on the list can verify it. If you would make a case study however on each claim, you'd probably find that in 90% of the claims , it is plain wrong. Of course other changes may influence the problem too, such as changes in perimeter setup : DNS, Firewalling , routers, and so on... M.