If the address number that you are looking for cannot be input is probably due to the way Navteq set the house numbers ranges database to specific zones within the same street based on the city/town location.
Even if the Post Office is saying that, for example 1234 NW 1st Street is in Ft. Lauderdale, Navteq insists in saying that it is not in that city because it only accepts house numbers up to 1000 for Ft Lauderdale for 1st Street. The 1234 number in 1st Street is only available in Lauderlakes because the allowed range of numbers of the same 1st Street is above 1000 for that city.
Pretty messed up, if you ask me.
Sometimes it helps some to enter the street and number first and then the city. At least this way it is going to give you the "correct" city.