I covered this in another post here in the last couple of days. We have had a high volume of orders for everything (not just QDX) following the very positive ARRL review of QDX in the March QST magazine. Several items ran out. The component sourcing, manufacturing and shipping time is in several cases up to 3 months (this applies to QLG2). I already had more QLG2 on order but they did not get here in time before my current stock ran out early due to the unexpected high order volume. 

Ideally I should have messages posted all over the shop advising the delay but it is hard to keep up with everything and administer such things; in some cases such as QLG2, the kit is also an option on many kits (including ProgRock2) as well as on its own shop page. 

Anyway the new boards are in Istanbul for customs clearance, I should hopefully have them in hand by this weekend then we can try and catch up on the backlog as fast as possible.