Aircraft deliveries S2

Hello.

I play S2 server (non aircraft leasing chalenge). Server date is 3 jan, 2001.

I ordered new aircraft A340-600 which will be delivered august 14, 2002.

And than i ordered A330-300 (which is in same family like preordered A340-600) and that aircraft will be delivered September 11, 2002.

Why is deliveri after A340-600??

If i want to fly ordered aircraft A330-300 i must wait to "deliveri starts" A340-600. In the past for this aircraft must wait 6weeks for production starts and 3weeks for deliveri. So if i want to fly A330-300 i must cancel orded for A340-600 and A330-300 and order new aircraft A330-300 which will bring me up to 210,760,000$ costs.

Any help? is this issue? Why is this in that system?

Sorry for my english