Hey Greg, I'm intermittently getting the problem Ginger has with the forum on Firefox, and it's correlated with also not being able to upload photos (The photo uploads, then says "Failed" rather than showing the photo). Logging out and then back in fixed it for a while, then it happened again after a little while. i also had an issue with logging in. It just did it again so I took some screen shots for you.
I also experienced a strange issue with logging in after the forum started doing the aforementioned thing (photo #1). I logged out (no problem), then clicked the "log in" which brought up the normal pop up window, but when I entered my info, it gave me a "this connection is not secure" warning (photo #2) and redirected me to another page (photo #3), from which I was able to log in with no problem. As you can see, since I am able to upload the photos to this post, the logging out/in has temporarily fixed it again.
ETA: I am using the latest version of firefox on a macbook pro with OS 10.9.5.