Very Strange

We are booked on the VS005 on 25th March. On 'My Booking' section it shows our seat selection on an A340-300. However when you make a new booking the grid shows the flight is operating an A340-600. I have rung VS who confirm there is an anomaly but seem bemused and advise that I keep an eye on things. They will report it to their website managers but thats about it.
Has anyone else experienced this? I like to request our seats and if there is an aircraft change, and our booking has not been updated then I can't update our seat request.
Any thoughts?
Has anyone else experienced this? I like to request our seats and if there is an aircraft change, and our booking has not been updated then I can't update our seat request.
Any thoughts?