Cheers Steve.Pay day coming up and a chance to buy more unobtainium for my ride.How many XBR's do you think are left in this country? They seem to be breaking them for parts and didn't sell very many.Mine does the cutting out as you stop trick now and then"they all do that sir" as once quoted. 
There still seem to be quite a few XBR's around although they are becoming 'Classic' now. They are probably the most common single in the club. As for the cutting out thing, yes they do all do that and it is annoying. You might want to know they also have the following other things:
sticky/ sieze front calipers - they need cleaning from time to time, if you ever take the head off you'll probably find a crack from the plug hole to one of the valve seats - don't worry they all do that too.
Finally if it's been standing for a while, you may find that when you kick it over you've lost all compression - don't panic! they do this but i've no idea why. Just keep kicking it over and eventually compression will return ..welcome to the wonderful world of the XBR!! ( actually they are damn good bikes and generally very little trouble).