dns failure only in browsers

Hi,

I've got a windows 7 machine connected to the internet through a gentoo linux firewall/router/proxy.

I used to have this problem a while ago on windows xp but worked around it with dns hacks on my linux box. This time I want to find the actual cause.

As of today, if I go to IMDB, most of the CSS files fail to load. Trying to get to the url directly, firefox and chrome both tell me that the IMDB cdn server can't be found. Running nslookup from the windows 7 machine managed to resolve the hostname perfectly. It also works flawlessly from the linux box.

I have transparent interception on port 80, going to a squid proxy which should perform all the DNS queries. It seems that browsers (firefox and chrome...untesed with others) still seem to be trying to perform DNS lookups themselves and for some reason, fail for certain addresses.

I have no idea where to start debugging this, any tips would be appreciated. I can supply any other information as necessary.

Thanks

Ok, since writing that last post, the browsers now work on the hostname I manually looked up. It looks to be something caching bad responses. Why the responses are bad in the first place I have no idea...and caching them as such is really annoying.

I should probably note that this problem mainly seems to occur with CNAME entries that redirect to big cdn providers (in this case Akamai). the OSdir website was one that failed a lot before.