BK - is it possible that the machine on which you are burning hundreds of caloris with little effort is actually the one that is broken and is over reporting your caloric loss>
It seems to me (based on the output of the machines I have been using at my gym ) that the machine you were using to day was probably giving you a truer reading ....
I second this. Going off of the treadmills i have used, and I've used many at my gym and they all seem to agree with each other on speed and calorie count, I think your preferred machine might be the flawed one. The speeds seem more accurate on the one you used to day, and i know the calories burned made more sense. Treadmills as a rule don't burn calories at a particularly high rate, and to burn almost 1000 calories on a treadmill in such a short amount of time you'd have to be going a breakneck speed.
Also, did you look at the incline setting? Was it the same on both machines?
<nod>
-Which is why a lot of people - myself included - place a towel over the display panel while they're running. No two machines are alike, and it's always best to gauge your pace and exhaustion level on how you feel and not what you see. To burn a 1000 calories in one workout, run session takes a LOT(!) of work and exertion.
*And does the machine really "catch-up" to you? That sounds little suspect, unless you had selected some sort of program on the machine that increases and decreases your speed at certain intervals.
In any case... I hope you made it to the Public, and I hope you at least like
Road Show.