Ok some more stuff that does not work.....
Disabling port re-direction on the router.
Disabling Dynamic DNS integration on the router
Moving the client into the router "dmz"
Installing a cheap Nvidia card I had hanging about and trying to use that.
knocking on 12 hours and one patch now. Does anyone have the same symptom? it's listed as a "do not report this" bug on the support page so I guess its not just me.
Very, very frustrating.