I reciently upgraded my speaker wire to the sound king wire from parts express. This was roughly 3 months ago. Last night I was working on the back of the reciever and I noticed the green oxidation buildup inside the new speaker wire. All wires were cut, stripped, and fitted to a bananna plug (screwed in the wire for max contact area). I then tinned the ends. I've never had any problems in the past with cheap speaker wire or even the monster speaker wire I use on the mains. Was there something I should have done to prevent this oxidation? What could I have done? Or is this wire just more prone to oxidation? Could the way I tinned the wire have an effect?