Hmmm. I have never tried re-testing when surprised by a result. I may start to… I was enjoying the thought that my morning BGs are showing an improving trend today, until I got to lunch time and I was at 11.1, instead of the usual near hypo I am used to (part of my problem with fixing the DP).
I think there may have been a couple of other occasions too, as I don’t trust my feelings of being high (I have felt ‘high’ right up until crashing into a hypo before…) so just assume the meter to be right. Also, I was only aware of them not being accurate to within less than 1mmol or something, rather than giving completely false readings!