Pd version 0.43.4-extended 20121215. Mac OSX Lion
Please use the attached canvas-test.pd:
1. open it: scroll bars are displayed
2. widen it a ittle to make the scrollbars disapear
3. reduce it so that the window limits are close to the grey canvas limits and before the scrollbars come back
4. save the patch, then close the window
5. open the patch again: scrollbars are back!
Note: with pd-extended 0.42, the window looks exacly like it was saved.