I'm using the scale since a couple of weeks now with some fluctuations in weight which I considered feasible (75 +/- 1kg). However today the scale showed only 72 kg so I stepped off and back on and - guess what - it suddenly showed 76 kg. Next try 73, then 74.6 and finally 74.7 for the next three trials. Has anybody else noticed this unreliable behavior? I'm using it on a tile floor always in the same position (after taking it out from below the sink).