There is an XML error in the 3.17 Civ4_UnitClassInfos.xml file regarding the Ship Of The Line. The entry for the Description tag tag reads TXT_KEY_SHIP_OF_THE_LINE where it should read TXT_KEY_UNIT_SHIP_OF_THE_LINE to correspond with the same entry in the Civ4UnitInfos.xml file. This error does not affect the unmodded game as far as I can tell but can show up when modding anything regarding the Ship Of The Line.

Cheers,
ripple01