Hot Foot are you doing any strengthening exercises? Make sure you always stretch out your calf muscles as well and you need to stretch both the soleus and gastronemus. I find it most effective to stretch out my calves using the bottom step of our stair case. I stand on the bottom step I bend my left supporting knee slighly and lower my right heel over the edge of the step until I can feel a stetch in my calf upper muscle. I hold this stretch for 30 seconds then I repeat on the other leg. That stretches out my gastronemus (the top of the calf) to stretch out the soleus I lower both my heels over the edge of the step so I can feel a stretch in the lower part of my calf and hold for 30 seconds.
To strengthen your achilles you can try balancing on one foot, or balancing on a wobble board but I found this exercise quite useful:
http://www.sportsinjurybulletin.com/archive/achilles-heel-injury.html