Before I changed out the DHS linkage I would make sure the rod ends (heim joints) were clean and not sticking causing the issue. Maybe spray both of them with some carb cleaner or brake clean to be assured they are free and not hanging up. Also check the they are centered and have not become twisted and in a bind from a loose lock nut on the adjuster, they must have full rotation on their axes.
For those who have not seen it here is video of what the DHS shifter linkage does
http://www.dhsracing.com/Pictures/dhs-11252.mpg