I'm booked on VS9 on 28th August (the outbound leg for VS10), and have been allocated 35 A & C, which don't exist on an A340-300.
I can therefore only assume (hope) the A340-600 has been allocated to this route for the summer season.
Hi mavml
Do you have a VS booking reference?
If you log into the Virgin Atlantic website and enter your booking reference (and a few other details) in 'Manage Your Flights', you should be able to access a seatmap for your flight (under ÔEditÕ your preferences), and this should tell you whether its an A346 or an A343 (though judging by the seat numbers, its the A346)
If you are at all unsure, just compare where the WCÕs are located in the PE section. (they are not in the PE section on the 343 à but a few rows back down in EC)