In the attached patch, a subpatch is saved with an horizontal position wider than my main screen (#N canvas 1818 ....).
If I use two screens, with the main screen on the right, the subpatch is opened out of the screen, and I can't see it or move it. If I only use one screen, it is opened normally inside the screen.
My setup is main screen on right : 1280x800, second screen on left 1920x1080.
Tested on pd-extended 0.43.4 and pd 0.45.3. OSX 10.6.8