Ok.. Found it... It's ok...
But looks there is a bug or something...
To appear good I changed the line
args.header.html = args.header.hours + ":" + args.header.minutes + " *";
to
args.header.html = args.header.hours;
I removed the minutes and they appear anyway.. but good.
I think it was when I switched to:
dp.cellDuration = "15";