MBA 2012 not cooperating with 27" ACD

[BBman]

I have the new MBA connected to an external 27" ACD, my problem is that any usb external drive hooked up to any of the display's hub usb ports are getting extremely slow(1mbps) speeds.

Connecting the external drive directly to the MBA has no issues and I am getting full speeds (30mbps).

Why is this happening? currently on mountain lion.

 

[BBman]

Figured it out! you have to connect the USB cable to the computer first then the mini display port after. After this I am getting full USB hub speeds every time.

Cant believe it took me this long to figure it out but if anyone has this same problem now you know!

 

[iAppl3Fan]

Figured it out! you have to connect the USB cable to the computer first then the mini display port after. After this I am getting full USB hub speeds every time.

Cant believe it took me this long to figure it out but if anyone has this same problem now you know!

I think something is up as what you are doing sounds more like a workaround to a problem rather then addressing the root cause. It shouldn't matter which wires get plugged in. Maybe test it a few times and take it to apple if it persist?