This sounds related to the bug posted by Jeff: "Gems - 126.96.36.199". I assume its the same database? The problem has to do with multicard ballots sharing a plate -- in this case the back. I am looking into it. In the mean time, Tab posted a work around in response to Jeff's report earlier.
PS: Nice to see that the title of first bug report since my "mailing list policy post" remains competely devoid of meaning. I look forward to the upcoming bug report "puerto rico database -- different than last one".