This is the first I have seen or heard reported on this forum of breakage at the location you are showing.
What I would do in this situation is on the next shaft that you get, shove a wad of paper into the shaft so it rests just below the pedal, then squeeze in that white Locktite marine epoxy ( http://www.homedepot.com/p/Loctite-0-85 ... /100371825
) filling the void, put the pedal back in, then put the cap on the end of the shaft. If you can shove a small drill bit into the epoxy along the sides of the pedal on each side, even better (those drill bits are really strong, and the epoxy bonds to the flutes very well, don't worry about galvanic corrosion, the drill buts are mostly chromium and cobalt, they don't rust easily, and if buried in epoxy they will be in there forever. If you spread a little grease on the pedal threads, shaft, and pedal face before insertion, you will be able to remove the pedal afterward if needed). With the locktite marine epoxy you have plenty of work time so there is no rush, just wipe away the excess before is sets up. Do not use 5 minute epoxy, it does not hold up in water (only marine epoxy).
If you want extra assurance (but not as pretty), after assembly you just wrap high test fishing line (the braided kind they use for sharks (not mono-filiment) around the post at the top (after the pedal is installed) about a dozen turns should do it, then cover with epoxy (like I said not pretty but it will be very strong). You can also probably use guitar string, or fine high test stainless wire if available as well, again if buried in marine epoxy corrosion will not be a problem. If it were me I would do all three fixes ( including the drill bit trick in the area I described earlier) on any new shafts you put on the boat. Spray paint it black when done or else people make fun of you ( LOL).
I'm sure it will be a while before Hobie can address this known material problem and new shafts hit the streets (they are on the problem), these simple fixes will keep you from getting hurt or stranded in the mean time, and only take 5-10 minutes to apply, and only cost a couple dollars to do.
Hope this helps