You might have a look at my QoS script, because it is set up in a similar way to yours, but I know it works:
http://forum.mikrotik.com/t/fasttrack-friendly-qos-script/102401/1
I suspect your issues are due to the way you are marking the packets rather than the queue settings. Are you using fasttrack on your device?
Make sure you are monitoring the “average rate” in the “statistics” tab for the child queue trees as you are doing your testing.