[squid-users] Cache not refreshing

Hi. I don't know why, but earlier today, I tried to load a page and it
showed a 404. However, the page was there.
Some other machines here showed the same 404 page when trying to get to
the address.
Only when forcing a refresh did the page really refresh and showed its
content.
Is this a browser issue (using Mozilla Firefox on my machine, and IE on
others), or is it squid?
Given the fact that I never entered the page before, and it still gave
me the 404, I figure it might be squid.
What are the relevant options for these kind of problems?

Thanks!

-- 
Bruno Lustosa, aka Lofofora          | Email: bruno@lustosa.net
Network Administrator/Web Programmer | ICQ: 1406477
Rio de Janeiro - Brazil              |