I am encountering problems with the queue tree similar to this post: http://forum.mikrotik.com/viewtopic.php?f=1&t=72998
In routeros 5.xx I had been using 2 queue trees whose parents were global-in and global-in, that were set to a Max-Limit of our internet connection speed. Each of these parent queues matched 4 packet marks that corresponded to 4 child pcq queues with different priority levels. After upgrading to 6.2 I changed the 2 top level queues to use global as their parent instead of gobal-in and global-out, but even after that none of the queues were showing any traffic passing through them(packet counters weren't incrementing).
To test I disabled all existing queues and created a new queue(queue1) under global and set it to only match one packet mark and a child pcq queue(queue2) under it set to match the same packet mark. These 2 queues seemed to work and showed an incrementing packet count. I then set queue1 to match a second packet mark and created a corresponding child pcq queue(queue3) set to match the same packet mark. After this queue1 only incremented at the same rate as the second packet mark, queue2 did not increment and queue3 incremented at the same rate as queue1. After this I set queue1 not to match the second packet mark, however it continued to increment at the same rate as the second packet mark, queue2 did not increment and queue3 continued to increment at the same rate as queue1.
I am using an RB450G. I would prefer not to post my configuration on the forum, but can send them via message or email if it will help.