From the timetable on Virgin's website it would appear that the Sunday MAN-Orlando flight ceases in mid November, to be replaced by a weekly Barbados, so number of flights remains the same. It also appears that they will be running a couple of extra Orlando flights early in November.
You have to wonder whether Virgin should be looking to add a second flight more regularly on the MAN-Orlando route, as a cursory hunt round their website shows little availability for July 2006 in the weeks before the schools break up, let alone during the holidays themselves.