Best FLAT Panorama-Sticher for EF-S 10-22mm ??

Hi -- I've been going crazy trying to figure out how to shoot indoor realty shoots using a panohead (which is pretty much properly set-up) and my EF-S 10-22mm, aligned vertically. I'm not looking for 360-degree VR shoots, just trying to stitch 3 consecutive shots together so that they don't have rounded crown moldings at the ceiling once stitched together. I've used PTgui, DXo Optics, PanoTools, Stitcher, and about 4 other softwares, and nothing seems to eliminate the curves when stitched (else it gives me these great warped 3-D pano projections, NOT what I want). I've also tried other lenses, with the same hurdle, and yes, the entrance pupil of the lens is what I pivot around. So anyone: why is this so difficult, and what's the solution I'm starting to go towards a T-S lens with flat-stitch technique, but geez, with all the software out there, doesn't anything make it a quick-step process with what I've got???

Thanks !!!

Kinda hard. You'll probably have to correct the distortion in each image then stitch them. Shooting more frames with a longer lens is another option.

Thanks, Tim, but I've actually tried to "undistort " them ahead of time, too, and it doesn't eliminate the problem at all. It seems to have something to do with the types of rendering-projections the pano-softwares do (I've tried all the different renderings, though, and nothing elimites that). When the rooms are small, as they often are in S.F., longer focal lenses don't really help, unfortunately; however, the wide-angle ones make every couch seem 20-feet long (!) Hence trying to shoot 2 to 3 shots vertically, stitch, and then crop out the tons of floor and ceiling. But thanks ! [love NZ -- I played a month "on trial" with the NZSO, as co-finalist for the CA position ... would have loved to have been hired !]

Why don't you try taking 2 or 3 times as many pictures to stitch together, so you're staying closer to the center of the lens, and keeping the initial distortion down?