Basically the page never loads, it just gives me that blue bar but never reaches the finish line. I've reset the cache, rebooted, reset Firefox entirely and will now try and reinstall. Hard to see what else would make this go away. Back to Safari I will go.
I wonder how this factors into the 99.999% uptime guarantee? I presume since the IMAP is still working that the uptime is met...though I have to say this really puts the idea of a completely browser-based lifestyle in question.