Is there something else I'm messing up?
reread the last sentence of my last replay:
"511 Main, PO Box 111"
will cause the import to think that the first part is one row and the second part is another row.
the comma in the value:
511 Main, PO Box 111
is messing up the filed count (since commas are used to separate fields, they cannot be included in the field data)