Does the secondary allow tilt adjustments? I have the cat's eye set as well. I rotate the secondary around its axis until the cross hairs of my sight tube are centered in the hole in the cat's eye triangular center mark. Then I use the cheshire and center the triangle as described in the instructions. At this point the autocolimator usually has the triangles all in there, but spread out. My secondary has four screws I can use to tilt it without rotating it to get the trinagles to stack up. I usually don't need more than two iterations of cheshire, autocollimator, cheshire... to get everything all lined up.

Hopefully this helps. Sometimes just hearing the procedure in someone else's words can help.

-Brian