wspeed*.png display only knots

[Weather Vienna-Schafberg]

hy,

i have a problem with the windspeed images, the week, month and year images display only knots, the day images display km/h (what i want).

From my images.conf:

wspeedweekcomp.png      "Wind max./Böe"                 km/h        0   138
wspeedmonthcomp.png     "Wind max./Böe"                 km/h        0   139
wspeedyear.png          "Wind (~/Stunde)"              km/h        0   23
hiwspeedyear.png        "Wind max. (~/Stunde)"         km/h        0   29

show me only knots graph

but

wspeeddaycomp.png       "Wind max./Böe"                 km/h        0   137

works fine in km/h

i have also testet
wspeedweek.png          "Wind (~/Stunde)"              km/h        0   120
and it shows only knots to.

and yes, i have km/h selectet in the wview management ;-)
the normal parameter works fine and are in km/h.

is this a bug or have i made somethings wrong?

cu
Schafberg