As the OP of that linked thread I can confirm that one of my meters is defintely lying. The problem is, which one? I am getting differences of 5 mmol/l even when confirmed by repeat readings. At the moment one of the meters is consistently 2 mmol/l higher than the other on the same blood drop, and it makes no difference which meter I use first. So we do not always get accurate readings, and I am convinced that one of my meters is sensitive to something other than glucose in my blood. Maybe lipids, or protein or salt. The meters use different sensor technologies (i.e. enzymes) so it seems to be inherent to the design, not due to simple accuracy issues.