Strung plenty of these, here are some tips.
When stringing the mains you double pull them, and so only pull tension from the head.
Don't mirror the left side mains with the right side. If the 1st left main (1LM) goes below the ring, the 1RM will go above it.
Some rqts have the double barrel grommets. You need to make sure you use the right holes when stringing the mains otherwise you'll end up with the wrong weave. In short, if you put the main in the top hole, the cross will go in the bottom hole and its 1st weave will be over the 1st main it comes too. Usually you'll string 1 side of the rqt with strings in the upper hole, while the opposite side the mains will be the lower hole. But you also need to make sure that the way you loop the mains around the power ring is right too otherwise you'll end up with the problem that Irvin has stated.
If unsure the best thing to do is string the 1st 4 mains on either side and then 'test' the crosses with a scrap piece of string.
Hope this helps and that I haven't made it sound too complicated.
Babolat Strike 18 x 20; Wimbledon stringing team since '04 - Head Wimbledon stringer '14; Babolat stringing team '10-'14. Twitter - @therqtstringer