Walter Montego: I remember when I was studying at the English institute I'm teaching at right now, we would have very confusing questions with have to and must. They'd give us sentences such as:

All of us ..... obey the traffic regulations.
I ...... buy a loaf of bread on my way back home.

Etc,.

I really didn't know in which I had to use have to an din which one must.

The examples I gav eyou are just things that came to my mind. So basically the answer to both of them may be the same.