It could also be the pilots reducing speed from 250 to flap speed? Typically 210 I think for stage 1 flap on a 73. Then again, this rarely happens at FL80, more like 5000-3000ft when nearing approaching localiser intercept heading.
Otherwise, I'll pass on it. I thought it could be something to do with the cabin crew doing their final checks? so they level off for a while for a bit of "steadyness" and the pretty women goes into the flightdeck with the "Cabin Secure for Landing" thing.
cheers
obk