+1 on taking the rubbers off, complete junk.
Put in this stuff:http://www.apsltd.com/p-15354-board-carpet-adhesive-backed-per-ft.aspx
Its a white carpet type stuff... theres a picture if you look under one design, v15, daggerboard...
I have had this in my boat for 2 years and my boards don't budge. They are actually a little hard to get up at times, we usually mclube them each morning. But I think that could be solved by trimming the stuff down or using less.
Shoot me a PM if you'd rather buy it from me than APS.
I actually have some of this left over from my Hobie 18 project. Are you using this in place of the carpet just below the decks surface? I don't know if our dagger trunks are the same. My Infusion is hull number 1 back when the boards were gybing. The bottom has since been bogged in but I don't know if the deminsions up top were the same as current production. This could be part of the issue as the dagger boards are new. Maybe they used to be thicker.