I have only every owned Janome's and I have never had this problem, neither has my mum who also swears by them.
Im thinknig it may well be somehting stuck in your foot, or perhaps its 'sticking' bit like an accelorator in a car. Is it a metal foot or a plastic one?
I really wouldnt recommend gerrying your wires together, thats is asking for trouble! Fires, electocution, heat build up just to name a few things you are asking for if you did this. Very dangerous indeed.