after searching some time, I found this post here very helpful to switch off static navigation for the internal Qualcomm GPS chip:
Open your favourite registry editor, and search for
Mine was set to "2", and I got the bad behaviour when slowly walking or geocaching.
Switching it to "1" led the GPSr to send each position without modifications or smoothing directly to the internal com port: Perfect!
Now my Kaiser can really replace the old Wizard with external SirfIII-GPS!
Hope someone searching for i.e. Geocaching, Walking and Jumping Locations happily find this thread.