This might be a little bug but it is a kind of boring if one is used to use the testpage for testing the printer's capability and correct setup after configuration. Since CUPS has been updated to 1.7.1 recently, the testpage no longer works as exspected and did before - amongst other things like cleaning head for ink printers or a calibration page (using HP OfficeJet 8600).
there is no maintainer for this port, so providing a patch would help a lot
Since ports r410825 this should now work if you have both cups and cups-filters installed.