I've never seen a problem like this in my 12 years of working on the web. Even with Javascript disabled (in all browsers, with all users on different computers), a field that gets focus then loses it to the previous form field. I thought I had some rogue jQuery somewhere but couldn't find any... then decided to disable Javascript and see what happens. The same problem exists.
What the deuce kind of wizardry is this?!?
Attached is a link to a screencast demonstrating the issue. Note that the first bit shows the problem with JS enabled (as demonstrated by the presence of TinyMCE toolbar) and the second is without (as demonstrated WITHOUT TinyMCE).
Help?!