I have the same issue with the ceiling sometimes. When I add matching points I always remove the ones that PW5 put in. I have found that sometimes theirs are way off and if you don't remove them it will never stitch correctly. And if it's a ceiling issue and there are no points I can find I will just go into each around scene and double check the stitching points and add as many as I can. I find that by adding a lot of "known good" points it will stitch with little or no points on the ceiling.
Hope this makes sense.
Nikon D300, D3s, Nikon 10.5 lens, RingT105N+Footplate+MrotatorTCPs, Giottos MT9261 Tripod, Manfrotto 410 Jr geared head.
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