Mikrotik reporting incorrect interface statistics

I currently have a configuration where by I have implemented transparent queuing.

The queing is working correctly. The issue I am experiencing is that Mikrotik is reporting exactly double the traffic passing any particular interface.

I have a monitoring box running cacti on my network. I am monitoring my Mikrotik host and it is reporting that the interface is operating at a maximum of 2Mbps. When I check the Interface Statistics on the Mikrotik its self via the web interface, I have a graph that reports double.

Via Cacti:
cacti-vlan15-br01.png
via Interface Statistics:
vlan15-br01.gif
My queues have had to be implemented using a 4M limit, where the actual throughput is only 2M.

I am running Mikrotik 3.14 at the moment. I am cautious to move to 3.15 due to the fact that my hardware is an Intel system with a Core 2 Duo processor. The reports from 3.15 is not encouraging.

Can anyone else confirm if they are experiencing the same problem?