Jib lead slipping forward

[TimPorter]

Has anyone had issues with their jib lead slipping forward?  I am having an issue, on only the port side, where the lead will slip out of the whole and slide forward.  I have ensured that the "pin" is down in the hole, but I am guessing that it has enough play on the track that it comes out and slides forward. 

[Dean Nelson]

I solved this problem by putting a slide with a screw pin in front of the slide with the spring loaded pin.  The block is on the rear slide.  The jib sheet is dead ended on the front slide.  This allows finer adjustment than when using only a single slide.  Additionally, on windy days the spring loaded pin slide can't accidently slip and go any farther forward than the screw pin slide.