sparks keep dropping out?
 

When I first ran my car I had no trailing plug firing so I found out by accident. New plugs and all good. Bearing in mind I have done bum all miles O keep getting strange running problems usually at idle where it will suddenly go a bit fluffy. I think the problem is plugs keep dropping out periodically. I noticed it the other day on first start after rebuild. Was running fine but sounded a bit fluffy. I went to check the timing and found L1 dead. 10mins later idle went clean and sure enough L1 was back to life. First putting for MOT yesterday and went generally well. On the way back it went a bit fluffy when I got t a junction and the rest of the way home. Got the timing light out and guess what.. This time L2 and T3 dead?! Fired up today like a bag of crap so I pulled leads and plugs and it got worse. Swapped leading HT leads and worse still and eventually I think it just flooded. So now I have pulled all leads and plugs and fired over engine with a plug in a lead checking each coil (using stock 20b coil packs by the way) all of them speak fine. Old leads possibly a bit weaker than my REA spares. Resistance on leads in the car is about 11ohms and REA is about 5ohms? Presume that is not and issue. If not what could it be. Can a coil stop and start. Could my Microtech ECU be messing about intermittently or is the rich idle 10.9-11.2 clogging plugs out?
please help.. I just got road legal and now I am parked up!