EyelinkDoTrackerSetup bug?

1
It seems like there might be a bug in EyelinkDoTrackerSetup or related
functions:
If I run this code, then calibration has a gray background, and yellow
targets, while I explicitely ask for a white background.

%------------------------------------------------------------------------------------------------------------
el=EyelinkInitDefaults(window);

el.backgroundcolour = 255;
EyelinkInit(0, 1)
EyelinkDoTrackerSetup(el);
%------------------------------------------------------------------------------------------------------------

But, when I set el.callback to an empty matrix (which makes
EyelinkDoTrackerSetup use the 'old version' of the eyelink setup), then
it works fine:

%------------------------------------------------------------------------------------------------------------
el=EyelinkInitDefaults(window);
el.callback = [];
el.backgroundcolour = 255;
EyelinkInit(0, 1)
EyelinkDoTrackerSetup(el);
%------------------------------------------------------------------------------------------------------------

Could this be a bug in the new version of the eyelink setup, or is there
a new way of changing the eyelink settings too?