Update
Had a rare success for a couple of hours then I can't connect again. - I Get the usual time out.
Log files attached.
The only way I get readable log files is to use the Lenovo provided graphics drivers.
I thought I'd have a go with a Broadcom BCM43228 card I bought to upgrade my laptop to dual band wlan and it worked for the couple of hours, so I really think the graphics drivers are the problem.
Why after all this time id there no definitive answer to what is going on in the background. The only advice we've had is to update drivers which is to be honest no more technical than what some numpty shop assistant in PCworld would say.
When there is a successful connection, the charms devices screen gets the tv into the projectors list and the widi audio device in other devices tab whereas with a fail the widi audio device doesn't appear.
It seems as though there is a negotiation fail between the graphics card and TV at the last minute to initiate a proper connection.