I keep having problems with FF not refreshing. The last one was
deleting the javascript for a reddit button and then refreshing 4
times to make sure it was gone. The reddit button no longer
showed, but instead there was about a quarter of a single google
ad showing, (also js). When I open the page in another browser
there is no reddit button, and no portion of a google ad. FF has
also done similar things with css.

I did delete my cache and cookies one time to see if that was
the problem but it wasn't, and of course I wouldn't want to do
that really often anyway. Is there a way to get ff to do a true
refresh? I'm using ff 3.