I also recently booked a multi-city itinerary using ITA Matrix and priceline. A few people recommended priceline as a good way to book the ITA Matrix fares. I soon received confirmations, reference numbers etc. The price was good and the process was pretty easy.

However, the airline's own website shows the booking as 'not yet ticketed'. The airline told me this was pretty normal.

The flights are still several weeks away, so I am not worried yet. I assume that priceline simply hasn't paid the airlines yet. Does anybody have any idea how long it normally takes for the tickets to be 'issued'? I assume, perhaps unfairly, that calling priceline will be painful.