Placing, removing, powering or unpowering redstone dust two blocks away from the junction will return it to the "off state". Powering redstone placed that far away, however, doesn't switch the junction rail into the "on state".
Video including the bug: http://www.twitch.tv/fryer92/b/512180774
At 13:00, when the redstone dust is placed, the junction at the track 2 blocks away turns.
Only tested in 14w11b.