Commuting - Anyone using iPhone iMapmyride and getting frustrated?

My iPhone mapmyride app has been giving me wonky distance readings lately (like the same 5 mile ride this week came in at 5, 10, 10, 5, and 30 miles). I have been using it successfully all summer, so this is a new problem. I even updated it, which was said to fix any gps bugs...

Anyone? What gives?

I use cyclemeter: http://www.abvio.com/cyclemeter/ . No problems, except for that my iPhone 3G runs out of memory sometimes and crashes (happens with other apps, too. Worse on GPS ones). No relation, just a happy user.

Cyclemeter doesn't have quite the 'social' aspects of iMapmyride, but it does do stuff like post twitter updates of my ride with links to the map. Funny story: my wife actually came to pick me up even though I didn't call her because she saw the tweets that I had stopped in an odd place for > 10 minutes (I had some problems with a tire patch).

Thanks for the tip, Praxis.
I am actually just looking for anyone else with the same issues, however. I have loved the app, just looking for a solution...

It must be a Mac only bug, I use the droid version without that problem.

The only issue I have seen is there is a hiccup when you leave an active wi-fi zone. I avoid the problem by just shutting off my phone's wi-fi before I start.