There was a preview of the next story quest for those who finished boss battle before November 20, 2007. After we won the black pearl there was a cutscene where Jack and Gibbs discuss the
Headstone which was buried on Padres. Jack wanted us to find the Headstone and the first task was to visit Valentina (the 2nd gypsy on Padres).
But the quest ended there and after they relaunched the boss battle in March 2008 these cutscene and task are gone.
So I believe the new story quest (finding the Headstone) will only be available to those who had finished Boss Battle.
