I think you need to add a line for SetDescriptionStyle to either "movie" or "video" to get it to show the releasedate
By default is sets itself to "generic" if it's not specified.
“audio”: All tags on audio screen above are substituted with Content Meta-Data.
“movie”: All tags on the video screen above are substituted with Content Meta-Data
“video”: All tags except <Directors> and <Ratings> are on the video screen above are replaced with Content Meta-Data.
“generic”: Only the <Title> and <Description> tags on the video screen above are replaced with Content Meta-Data.
Function preShowDetailScreen() As Object
port=CreateObject("roMessagePort")
screen = CreateObject("roSpringboardScreen")
screen.SetDescriptionStyle("movie")
screen.SetStaticRatingEnabled(FALSE)
screen.SetMessagePort(port)
return screen
End Function