I'm liking FF4 so far. I was using Chrome but they never fixed my endless "Sending request" bug, no matter how many times I and others reported it, so I'm giving up on them for now.
Open your proxy settings and uncheck "Automatically detect settings" and your "Sending request" bug will be gone.
Established technology tends to persist in the face of new technology. -- G. Blaauw, one of the designers of System 360