Apache CSS problem

[Victor Odhner]

I am building an Apache site on Solaris, including a css file.

The CSS was working, but I went to change some colors.  Now none of my 
browsers seem to be getting the CSS.  That's one IE on XP; one Firefox 
on XP; and Firefox on two Linux systems.

I'm using the Firefox "WebDeveloper" toolbar that displays the CSS that 
is in effect.  When I visit other sites, the CSS pops right up.  But not 
from my site:  the "Edit CSS" window comes up blank.

How might I have broken this?  Ever in search of a clue . . .

Thanks,

Vic