Trustworthy data

I've been having problems trusting my gadgets recently. My new Finis Swimsense is meant to be the business in tracking swim sessions - it's supposed to be able to determine stroke type and count lengths - in my 4km swim on Friday it was of the opinion that I did the last third backstroke and breaststroke (and at no worse pace, quite impressive if you've ever seen my feeble attempts at the latter). It has also miscounted quite a few sessions (my 4km came out at 4.025km, for example). I'm not concerned if it can't understand my drills but I expect it to get the basics right!

On Thursday I went to Regents Park and did two laps of the Outer Circle, starting and finishing at the Hub. You wouldn't know that from the map

http://connect.garmin.com/activity/105831213

Oh well, the swimsense got a firmware update on Saturday, and I'll be more careful to check GPS accuracy before starting a run next time (not that that's always a guarantee).