Star Ocean : First Departure says on the page (http://us.playstation.com/games-and-media/games/st
Not sure why, the URL is correct. If you click on the link, then hit the "search" button (the data is already filled in), it will lead you to the right item anyway.
Your link isn't correct as you included the closing parentheses in the link. If that's removed it works fine.
This is a problem with their website. It seems to me that every PSP game says it's also on Vita, even if it never made it to PSN. You may want to contact them about it. I never bothered since there are, unfortunately, better ways of finding correct info about their products.