Worked for me mostly fine as well. I was logged on at 6am ;-)
I did have one glitch where it would tell me it "could not make reservations at this time, try again later."
I was able to get almost everything I wanted,
even a BOG lunch!!!!
However, I was unable to get a San Angel Inn dinner

I replaced that by booking at Biergarten, but I will try again later. Then again, we have never tried Biergarten either, so I may just leave it.