Danno,

I'm not sure what you mean by the mast rotated 90 dergrees, but if I remember correctly the gin pole also has to have lines that stabilize its rotation. So you need a line that goes from the end of the gin pole and tied to the forward crossbar at the same location you are tying your trapeze wires. The trapeze wires keep the mast from swinging side to side as it's raised, and the gin pole wires keep the mast from rotating.