firefox always miss

[Cherife Li]

Hi all,

I'm using v1.1.2.

Given a .gif file(I'm just testing), IE and curl could hit from cache, 
but firefox never hits.

I through it was the "argued" Accept-Encoding issue, but things are not 
this simple.

I've read http://varnish.projects.linpro.no/wiki/FAQ/Compression, and 
tried the example there.

And I've tried to change the headers for firefox, even if left only the 
User-Agent and Accept: */*, emptied any header else.

Varnishstat shows firefox never hits or misses, varnishlog shows firefox 
  pass but fetch when I Ctrl+F5.

Could anybody guide me through?

Thanks.
-- 
Rgds,
Cherife.