Dilution = 14? That's very weak signal. It should be < 5. Speed calculation is always a bit of a problem. Try moving around at about 10 km/h and the speed calculation will be correct if the satellite constellation is okay.
Run.GPS calculates speeds on its own. It does NOT use the GPS speed as other software does. This is necessary because the GPS speed cannot be used at low speeds AT ALL because it fluctuates very strongly. If you run at a speed of 10 km/h, you'll get GPS speeds between 5 km/h and 20 km/h. So, using our own algorithms improves this, but you may see wrong values sometimes.
Hint: even if the current speed is wrong due to a weak GPS signal, the average speeds will normally be correct because they're calculated based on time and distance.
Hint: try increasing the speed smoothing buffer (Configuration > General Settings)
I am trying Rungps on my new Samsung i780. This smartphone has an internal GPS which works with intermediate driver. The GPS fix is good (9 sat and 14 of diluition) but the lat and lon readings keep change continusly and gps speed is above 4 kph also when not moving. I tried to use gpsgate software and a virtual com port but the problem was not solved. The only way to solve the problem is to use an external bluetooth adapter. Other software (like vito activetrace) works well with this device and internal gps.
Any suggestion ?