Take a break from running. How fast, and how far are you running, and how long has it been since you ran any real distances? I had what sounds like the same problem a few years ago because I went from no running to running frequently. I was stubborn and kept running regardless, and it got worse. I ended up taking two weeks off running, and I did a wierd stretch that hit the inner side of the calf alot better. Try doing your standard bent over toe-touch stretch, but cross your feet over so that your feet are side by side but the outer edges of both feet are touching each other, know what I mean? Also, try a different variation of the toe touch stretch with your heels one foot apart but your toes pointing in at each other and touching. I know it sounds really strange but it worked for me. When you get back to running, start out easy, you may feel like a wuss but at least you wont injure yourself while your body gets up to speed.