WiFi not enabled after processor/motherboard upgrade.

I installed Kali 2 on a dual core Atom mini ITX system (Intel D2700MUD) and it was working fine but rather sluggish.
So I decided an upgrade to an i5 should do the trick.
Swapped over to a Gigabyte Q87TN with an Intel i5-4590S ... Same memory, same hard drive, same Kali installation.

On boot up there was an initial delay where it reported a uDev Start Process was running (or something like that) but it then completed and I logged in.
WiFi is via an Alfa AWUS036H USB adaptor and its LED was flashing at regular intervals as was its on screen status.
Looking at /var/log/messages the USB was repeatedly being detected, flagged as not an MTP device and closed.

This never happened with the Atom version.

Any ideas/suggestions as to how I can get it recognised as an MTP device or disable the checking?

UPDATE:
This seems to be a USB issue, disabling the MTP probe stopped the message but not the problem.

Looking at /var/log/messages in more detail shows the Atom uses EHCI & UHCI whilst the i5 uses EHCI and xHCI.
This is the only difference I can see so far. Could there be a problem with xHCI?

[SOLVED]
UPDATE:
Deciding it was most likely a USB problem and after a bit of reading around I thought that maybe the new motherboard could be more sensitive to the USB power requirements.
Placed an active USB hub between the computer and WiFi and all is working now.