Most of you know this but I learned the hard way to make sure you change the code on your meter to match the code on your test strip vial. After a weekend of unusual highs, even before a meal , this morning I discovered I'd been using a code number of 22 on my monitor with a with a new test strip code of 9! Duh ! seems like the last 2 boxes of strips ere all #22. After calibrating with the control liquid, my numbers are back to normal, not 140 before a meal. Just a little lapse in the technical stuff can cause one big worries!