star ratings problem when using sidecars

[Phil]

I have dk set to write metadata to xmp sidecars only.
In 5.0.0 (on OSX) and 4.14.0 (ubuntu) I see the following behaviour:
dk always writes the line
    xmp:Rating="4"
to the xmp sidecar, independently of the star rating of the image. 
Changing the star rating does not change this line.
In contrast, the "acdsee:rating" and "MicrosoftPhoto:Rating" lines are 
set correctly.
This messes up the star ratings if ever metadata is re-read from the 
image (sidecar).
Does anyone else see the same thing?
Thanks