I had the EXACT same problem on my 03' Escape LTD.
It was my battery! About 2-3 weeks after having it flash intermittently and then stay on on my drives, while I kept thinking it was my airbag, I was leaving the mall and the car wouldn't start! My battery had completely died.
Now that I have a new battery put in, the airbag light doesn't come on anymore.
Incidentally, my battery light NEVER came on this whole time....I would highly recommend you change your battery if you haven't changed it in the last few years or so...