Coils and plug HT leads always a good starting point (sic) and can be worse in 'damp' rather than 'wet' conditions. Are there any idiot safety mechanisms such as sidestand cutouts? I doubt it, but it's fresh in my mind as mine kept cutting out the engine yesterday (I bypassed it for todays gathering and then rode off out of the pub carpark with the sidestand down - doh!). Was it dead on both cyclinders this am or just the one?