If it's truly Chrome that's giving the denial (not Squid) then try a different browser. If it's Squid (you should see a message that says squid is blocking the site) then take it up with the squid admins. It could be a simple configuration problem that they can fix.
Just because a site is whitelisted doesn't mean squid will like every page on it. Squid can be configured to do keyword blocking as well as IP blocking (black/white lists). The order in which the filters are applied can also be the source of "interesting" behavior.
As to the 25 kb/s limit - you do mean 25 k-bytes/s don't you? My last phone modem was 48 kbits/sec and even that would be totally unusable with most of todays websites.