Nothing is going to show you moving at .07MPH. Maybe you meant .7MPH?
The problem with any GPS indicating location at that kind of speed is that you are moving far less than the GPS error between updates. .7MPH is about a foot a second, and consumer GPS isn't accurate enough to even tell which direction you moved.
The GPS error can easily change by a quarter foot per second, even with WAAS and good satellite views, and can be much worse than that in poor reception conditions. That means the GPS is telling your chart that you are moving around in random directions all the time, and the chart display algorithm has to ignore those small movements in order to keep the cursor from dancing around rapidly.
There are some processing tricks that can let the chart track steady movement, but if you make a sudden change with the TM, your position could be way off for a short time. In order to really solve the issue, an inertial measurement system needs to be included in the hardware so the chart would find out where it was from the GPS, and then constantly get feedback on which way it is moving from the IMS. They are coming down in price and size, so you will see it someday.