I would agree it sounds like a dry joint.........
Ease the dash forward an see if anything around the speedo needs attention.
The electrical connection between the sensor in the hub and the loom is under the offside wheel arch. It might be worth checking.
The sensor has an 'led' at the end which flashes dimly when it generates a signal. I don't think this is the problem, but if you can spin the front wheel in the dark with the ignition on, you should be able to see the dim flash.
