dhtmlx scheduler unit view step issue

Hi,
I am exploring dhtmlxScheduler demo (java) and in the unit view i am using step 7 and size 7 just so that i can explore scroll feature, when i scroll to next page in the unit view and uncheck one of the employee the whole unit view goes blank. i tried using the vanilla dhtmlx scheduler in html and got the same behaviour. i am using

	// create units view
	DHXUnitsView units = new DHXUnitsView("units", "user", "Technicians");
	units.setServerListLink("users");
	units.setSkipIncorrect(true);
	units.setSize(7);
	units.setStep(7);
	planner.views.add(units);