How to remove a single object from the cache

Is it possible to remove a single object from the cache? My problem was that
I have a small text file which is scrolled on my home page. Yesterday when I
updated it, Squid kept serving the old one from the cache, even though there
was a new one. I changed the config file to not cache that particualr file, or
my site and reset squid, but it persisited. In desperation I deleted and re-built
the cache and the problem went away. I had deleted my browser cache, but
this had no effect.
The original entry in the log was a
TCP_REFRESH_HIT
whilst subsequent attempts were
TCP_HIT

I guess I needd to know why Squid did not fetch the new copy as well.

Cheers,

--
Simon Bryan                    sbryan@olmc.nsw.edu.au
Information Technology Manager sbryan@mpx.com.au
OLMC Parramatta