I use Firefox for going through email because it is very fast but use Internet Explorer when working on Webpages, graphics, javascript, etc as Firefox doesn't seem to work with all of them.
It's great for using as a tool for posting HTML on FR and has better built-in popup support than IE6. (Use the 'CTRL' and 'ALT' keys when a page won't load correctly to bypass the popup blocker.)
I use Firefox also. It's great for FR, really fast.And I don't get the popups like I used to, also.
..... but use Internet Explorer when working on Webpages, graphics, javascript, etc as Firefox doesn't seem to work with all of them.
I use NetCaptor or IE sometimes because Firefox has trouble with some Audio/Video stuff. Like my FR Pinger (audio) won't work on Firefox, but does on NetCaptor and IE. (I can SEE how many comment/FR mail I have on Firefox, but the pinger audio doesn't work).