Did you weigh-"eliminate"-weigh, or did you also do something else in between, like drink water or eat breakfast? That would explain the difference. Or maybe the scale was just being persnickety - they'll do that, you know.
My scale has two memory settings and one setting that doesn't save. I always check the one that doesn't save, and if I like the number, I'll do it again with one of the memory settings so it will be saved. Do you know how many times it decides to go up a smidge when I re-weigh to save the number?