even after laboriously following previous post, cannot cast from char to int

Hey,

Re casting char columns to int, I've worked all the proposed solutions from previous post-gres mailing list posts, but to no avail.

None of the ALTER TABLE proposed fixes worked for me, and now I have a new INTEGER type column created, I execute the following:

UPDATE zip_code_data SET county_fips_rev = CAST(county_fips as INTEGER);

...and this is what I get:

ERROR:  invalid input syntax for type numeric: "     "

What is this telling me?

Thanks,

Lille