Originally Posted by KingCanute

Once all of the seats that aren't blocked have been selected, it won't show you the seat map because there is nowhere for you to move to.

You can usually double check the seat map with a free account at expertflyer. Or keep checking back at QR - someone may cancel, freeing up a seat and allowing the seatmap to show again. In the meantime, your seat still shows confirmed so don't worry about it.