Twist the wires and change the length of the wires. It could be that you are at a length that resonates with the signal. If you ADD or subtract a little bit of length the problem may go away.

After you figure out your problem, one way to subtract a little, though you probably don't want to do this, is to cut off the connectors and solder the servo wires to the extension. I've started doing this to prevent corrosion in the extrension plugs from causing intermittent contact when coupled with vibration (a known condition), especially with my long winter storage periods. This keeps me from having to pull the extensions yearly to clean the plugs. Also, I've heard you can lose almost 1/2 of a volt at a plug... soldering virtually eliminates this.

You can also try an RF filter on your extensions.

Cheers and Good Luck!

I feel for you man... I went around and around for almost a month with mine.