Bit of advice/encouragement needed...

I've been doing regular 'barefoot' (in aqua shoes - tried au naturel but found I my feet could only take so much rough tarmac, and I'm doing this to improve my running form, not for some return-to-nature-and-be-at-one-with-the-ground reason) running for a few weeks now, but don't seem to be making much progress with the distance I can safely run and the resulting calf pain. I'm limiting myself to 2km per run and have built up to doing that 5 times a week on top of my 'normal' running, but usually by the end of that I can feel my calves tightening and sometimes even have to walk the last bit because it feels like I'm in danger of spraining something if I push it. On the occassions I have tried to run a bit further, I've ended up with a calf strain and having to take time off, and my achilles are permanently a bit tender (although his has been the case since before starting barefooting). Any idea how long it's going to take to adapt? I know I've got very tight calf muscles and I'm going for some remedial massage next week, so hopefully that will help. Maybe I'm just not giving my calves a chance to recover between runs or maybe I just need to be more patient...

I do enjoy my 'barefoot' running, and it feels like I'm doing it right - legs bent a bit more than normal, quick light steps, landing on fore/mid foot under the body then heel touching down lightly + nice and relaxed. Mind you I'm not sure I've got the hang of going downhill - even a fairly gentle slope - maybe because the angle makes it more difficult land in the forefoot? - any tips? When I put my road shoes on and go back to heel striking it just feels strange and like I'm pounding the pavement in comparison!