dns-related cache problem (squid 3.3.8)

[Dash Four <mr.dash.four@xxxxxxxxxxxxxx>]

I have the following problem: I use the "hosts" file to store static 
address mappings, usually containing sites which use geo address mapping 
(in other words, determine the ip address one is going to use depending 
on the geographic region the request is made from). One such site is 
youtube for example.

Squid caches web pages content from these sites, but when I change the 
IP address in "hosts", squid is still using the old IP address for some 
reason, even though I verified that the new mapping is used by the system.

In such cases, I have to stop squid, wipe out the entire cache and then 
restart squid in order for the new host->ip mapping to be used. This 
can't be right!

What I presume is happening is that somewhere along the line, squid is 
storing clear ip addresses in the cache (probably to speed up serving 
page content requests) and then it does not check whether that ip 
address has changed. If that is so, could this be fixed, because the 
idea of me clearing the entire cache every time I change one of the 
"hosts" mappings does not exactly appeal to me. Thanks.