Britannia Woes

As posted by me in the Britannia review I finally have mine and as previously posted it had a fault in that the motor wouldn't turn. I fixed that and left it for a couple weeks while I was away. I picked up a couple of Lenz Silver decoders and decided to put one in the "Brit", I had fitted a Le1035. A quick unplug and replug and hey presto job is done but all is not well! I have developed a short across the track pickups with the Silver decoder installed. I pulled it out and stuck it in an A3 that's getting weight added and it worked fine, back into the Brit and it won't work. I pulled the socket out and hard wired the decoder, short is still there. I've not experienced this in a RTR model before, plenty of times in kit built locos yes but never in RTR. Anyone experienced anything similar with a new Brit?

Ozzie21.