Unfocusing an html select field (drop-down) with escape does not work in Xul >= 25.
I can confirmed it did work in Xul 24 and is still broken in Xul 35.
Go to http://dpaste.com/ focus the select field labeled "Syntax" either with hints or by clicking on it
with the mouse. Press Escape either before or after changing selection (it doesn't matter). Field will
not be unfocused and you will still see "form/selected" in the echo area.
A workaround is to tab to a non-select field and unfocus from there.