TapDial used to work fine, until the last developer update. Go figure. 🙄
I get the same thing, ever since 2.1 update and now same issues under 2.2. You create a contact and it refuses to show up. After trying like 20x for some reason once my contact actually showed up, and then it was named SBDial and not the name of my contact. I'm giving up on this and am trying another app.
EDIT: I tried One Tap Dial from the Apple Store, which is currently free but will go back to 99 cents soon, and that app always pulls up an unnecessary splash screen before calling the number, so gives a delay in your call, which is annoying.
I tried CallMe as suggested above, and WHAT A COOL APP! It puts your contact photo on the SB for the person you are calling, which is very cool. Kinda glad I had this problem with TapDial now so that it led me to CallMe. A much better app, and it WORKS, and like you would expect.