Error on import

I am attempting to import a zip code database into a postgresql using
COPY.. but I am getting an error that the data type of the for longitude
doesn't match the table's data type (double precision)

'RROR: copy: line 1, Bad float8 input format '-73.0456

Any help on why -73.0456 won't go in is appreciated. Thanks!

Sample line:

0501,HOLTSVILLE,SUFFOLK,NY,NEW
YORK,D,U,36103,516,EASTERN,40.8154,-73.0456

and the table definition:

Column | Type | Modifiers
-------------+-----------------------+-----------
zipcode | character(5) |
city | character varying(28) |
county | character varying(25) |
statecode | character(2) |
statename | character varying(75) |
citytype | character(1) |
zipcodetype | character(1) |
countyfips | character(5) |
areacode | character(3) |
timezone | character varying(15) |
latitude | double precision |
longitude | double precision |