We can try enabling admin mode. I could not find the command to do this, but in the GUI there is a drop down under Switching>ports>traffic mirroring>port mirroring. Enable that and see if behavior changes.  I would also be interested to see of any behavior changes after a firmware update. Thanks 
Good Afternoon Everyone,  I am attempting to mirror two ports on my Powerconnect 7048 switch. One of them is a Trunk Port and the other is just a untagged port. I am not seeing any traffic coming to the destination port. Is there possible a bug in the Web management interface that is not applying this correctly? Running Firmware 4.2.2.3  Thanks, David
Powerconnect 7048 Port Mirroring