This issue is almost always because the number you have chosen was not a local number. Remember that even though a number may be in the same area code (NPA), it does not mean that it is necessarily a local call. This is why we list the town after you choose the state and area code when signing up. If you do not find the correct number for your town, you may choose the town that is closest. This can be risky so be sure look in your local phone book or call your local phone provider to get a list of towns that are in your Local Calling Area (LCA).
The reason cell phones work is that they do not require a 1 to dial long distance.
A quick way to test this theory is to have a person who was unable to call you on their land line try again by dialing long distance. (1+ area code + local phone number)
You will need to order a new local phone number to replace your current number. You will need to enter a service request to customer care to do this.