Funny you mensioned that as i just realised this started around the time i replaced it last year and done it ever since....a mate had a new coilpack he didnt need and gave it to me, so i fitted it as it was new, maybe its faulty.
I still have my old one, will fit and try tomorrow, one thing i dont get though if its coilpack, wouldnt i have loss of power too and even one plug not firing?
Thanks
Joe