On The Farm School Wagn - http://thefarmschool.wagn.org/Users_by_Zip_Code - you can see that between taysmom and Victor Slade something changes and there's a line break between names and zip codes. The HTML shows that before the change there are p tags around the zip codes before the change, and not after. But examimng the cards' HTML directly shows that they all have the p tags:
http://thefarmschool.wagn.org/card/edit/taysmom+zip_code
http://thefarmschool.wagn.org/card/edit/Victor_Slade+zip_code
Some of the zips have p's in them. some don't:
http://thefarmschool.wagn.org/Victor_Slade+Zip_Code.txt?view=raw
I'm guessing that when you say "examining the cards' HTML directly" you mean editing in tinyMCE and then looking at the HTML. But the moment you open it in tinyMCE it adds the <p> tag (though, of course, it isn't in the db until you save it).
That was it - thx for the tip re tinyMCE adding p tags and raw view