Transparent cache behaviour and complaining webdesigners

I've set up a transparent squid cache which seems to be working fine
most of the time. Though today several users complained about not being
able to see the changes they made to their websites.
They use IE for the most part and the all the sites in question are on
Apache servers.
When reloading in IE on their machine they get the old contents
consistently. If I enter the url in Netscape on another machine (which
hasn't accessed the page in question before) the old page comes up as
well. But by hitting reload the new content comes up and then it works
in IE on the other machines as well. So in this situation it seems that
a reload from within Netscape is required for squid to update the page.
So every time a webdesigner comes up and complains i simply enter the
url in question, get the old content and then hit reload and squid
fetches the new content. Strange behaviour? I think so.

I thought squid always checked the Last-modified header on the remote
end before sending the cached content?
How can i work around this without setting up cache deny acls for the
poor webdesigners?

The sites in question are:
http://www.arsinova.dk/
http://www.interresearch.dk/
http://www.gig.dk/

I tried testing a little.
129.142.30.80 is initially running IE5 then swithces to Netscape 3.04.
129.142.30.121 is running Netscape® Communicator 4.6 (FreeBSD).

Excerpt from access.log with comments:
# 129.142.30.80 hots Refresh in IE5 but gets cached content:
942086902.290 17 129.142.30.80 TCP_IMS_HIT/304 190 GET
http://www.gig.dk/HTML/etab_fyn.htm - NONE/- text/html
942086902.313 1 129.142.30.80 TCP_IMS_HIT/304 191 GET
http://www.gig.dk/HTML/marmor.jpg - NONE/- image/jpeg
# 129.142.30.121 hits Reload in the right-click menu in the frame:
942086918.065 8 129.142.30.121 TCP_MEM_HIT/200 7940 GET
http://www.gig.dk/HTML/etab_fyn.htm - NONE/- text/html
942086924.826 61 129.142.30.121 TCP_MISS/304 181 GET
http://www.gig.dk/HTML/etab_fyn.htm - DIRECT/www.gig.dk -
942086924.882 55 129.142.30.121 TCP_MISS/304 181 GET
http://www.gig.dk/HTML/marmor.jpg - DIRECT/www.gig.dk -
# 129.142.30.80 switches to using NS3.04 and enters the url www.gig.dk
942086975.329 2 129.142.30.80 TCP_HIT/200 1351 GET
http://www.gig.dk/ - NONE/- text/html
942086975.505 1 129.142.30.80 TCP_HIT/200 6626 GET
http://www.gig.dk/HTML/menu.htm - NONE/- text/html
942086975.507 1 129.142.30.80 TCP_HIT/200 486 GET
http://www.gig.dk/HTML/counter.htm - NONE/- text/html
942086975.507 0 129.142.30.80 TCP_HIT/200 1518 GET
http://www.gig.dk/HTML/top.htm - NONE/- text/html
942086975.510 2 129.142.30.80 TCP_HIT/200 2914 GET
http://www.gig.dk/HTML/omgig.htm - NONE/- text/html
942086976.465 1 129.142.30.80 TCP_HIT/200 6927 GET
http://www.gig.dk/HTML/marmor.jpg - NONE/- image/jpeg
942086976.476 9 129.142.30.80 TCP_HIT/200 4922 GET
http://www.gig.dk/Images/Background_gradient.jpg - NONE/- image/jpeg
942086976.476 3 129.142.30.80 TCP_HIT/200 5195 GET
http://www.gig.dk/Images/Godt_i_gang_logo.gif - NONE/- image/gif
942086976.476 3 129.142.30.80 TCP_HIT/200 6928 GET
http://www.gig.dk/Images/marmor.jpg - NONE/- image/jpeg
942086987.853 3 129.142.30.80 TCP_HIT/200 2979 GET
http://www.gig.dk/HTML/etab.htm - NONE/- text/html
942086991.986 5 129.142.30.80 TCP_MEM_HIT/200 7935 GET
http://www.gig.dk/HTML/etab_fyn.htm - NONE/- text/html
# 129.142.30.80 hits the reload button in NS3.04
942087007.801 49 129.142.30.80 TCP_MISS/304 180 GET
http://www.gig.dk/ - DIRECT/www.gig.dk -
942087007.934 23 129.142.30.80 TCP_MISS/304 181 GET
http://www.gig.dk/HTML/menu.htm - DIRECT/www.gig.dk -
942087007.955 42 129.142.30.80 TCP_MISS/304 179 GET
http://www.gig.dk/HTML/counter.htm - DIRECT/www.gig.dk -
942087007.956 40 129.142.30.80 TCP_MISS/304 180 GET
http://www.gig.dk/HTML/top.htm - DIRECT/www.gig.dk -
942087007.959 41 129.142.30.80 TCP_MISS/304 181 GET
http://www.gig.dk/HTML/etab_fyn.htm - DIRECT/www.gig.dk -
942087008.025 51 129.142.30.80 TCP_MISS/304 182 GET
http://www.gig.dk/Images/Background_gradient.jpg - DIRECT/www.gig.dk -
942087008.027 38 129.142.30.80 TCP_MISS/304 182 GET
http://www.gig.dk/Images/Godt_i_gang_logo.gif - DIRECT/www.gig.dk -
942087008.291 58 129.142.30.80 TCP_MISS/304 181 GET
http://www.gig.dk/HTML/marmor.jpg - DIRECT/www.gig.dk -
942087008.298 54 129.142.30.80 TCP_MISS/304 182 GET
http://www.gig.dk/Images/marmor.jpg - DIRECT/www.gig.dk -

In the meantime I will have to look at making acls for those users but
that is a suboptimal solution imho.
Thanks.

-- 
Hroi Sigurdsson
hroi@existential.dk