Error in PyLap Doppler shift output

[g3zil]

Extracting Doppler shift from the PyLap list ray_data using:
pylap_doppler= ray_data[rayId_min]['Doppler_shift'][N]
where rayID_min is the ray number that has grounded at required location and N is hop, 0 being the first, gives erroneously large and always-negative results. A dip test comparison between the PyLap output, the output from PHaRLAP itself (courtesy Dr Chris Deacon G4IFX) and my own calculation of Doppler shift from PyLap ray phase path differences 5 minutes apart is shown in the table below.

Gwyn Griffiths G3ZIL