I had a Harken XD kicker with a holt top block, 4mm vectran primary line and the primary kept getting caught between the sheave and the block (jamming the kicker tight). I replaced the primary line with a thicker 6mm Dyneema line and replaced the top block with an old style Holt block as used in the original lasers with a 3:1 purchase and still have the same problem. The old block did not have a bent kicker key like the new systems but I'm not sure this would have made a difference. What are people using? I am considering buying the Harken laser vang top block and a 4mm dyneema primary like this one: http://www.roostersailing.com/merch...ore_Code=1&Product_Code=2508&Category_Code=lk Any ideas why the primary line may have kept getting jammed? Thanks in advance.