First issue is a dead coil pack.
Cause: A cracked spark plug?
Full Story: Assumption, plugs were taken out and a cracked plug was replaced in error. Human error lead to the plug fault not being discovered till after 2 weeks of car being driven like that. Plug was replaced. Car was grand till she started to run rough again. Leads were changed as were two sets of plugs (one set contained one plug that was DOA).
History: This car had an 'extra' coil pack bolted on but not connect
Solution: Replaced coil pack and one lead with spares from working Activa.
Notes: Getting the bolts off is a pain in the ass. The heads rounds, if you are lucky they will shear, otherwise you'll have to grind of the bolts.
Parts: I am going to get http://www.ebay.co.uk/itm/300517689494" onclick="window.open(this.href);return false; and http://www.ebay.co.uk/itm/140899400701" onclick="window.open(this.href);return false; unless anyone here thinks it is not up to spec.
(I can attach pics if desired.)