Segment 12 appears to have an extra data value

[simsong]

Segment 12 in the each of the distributed 52 ZIP files appears to have an error.

The SF1 specification states that there should be 255 columns in each of these files. However, there are 256. It appears that the insert column is somewhere before field #129 that defines variable P037A001. This number should be a percentage, but it is clearly a population count in all of the files. The error also causes P038A001 to be reported as a numeric (that is, with a decennial point), even though it is an integer (it is a count), because of the extra value that is inserted.

Has anyone else encountered this?