JPG map calibration error

May be I'm doing something wrong, because I'm noob in this app. I have installed orux desktop 2.0.14beta on my computer and oruxmaps 5.2.3 android app on my galaxy s3. I found a JPG map (15x5 km area), inserted it in orux desktop, set time WGS global 1984, projection flat, no calibration file. Inserted two x., y map coordinates (found coordinates using MS paint), found gps coordinates in google maps, created ad uploaded in phone maps directory. then I opened it in phone as offline map. It appears, but with few kilometers mistake. I did map calibration and thinked the problem is solved. But when I start mooving, mistake (about 500m) appears again. I did calibration again, but even after calibration there was a mistake. I restarted software, but after that I can open this new map only in tracking off mode, if I turn tracking on, the world map appears.