I had to make a small website for a class.
If you click on the Resources link. The layout shifts a few pixels width to the right. All pages are linked to the same style sheet so I am not sure what is happening.
You need to force a vertical scrollbar to prevent page jog.
I noticed that the page in question is the shortest of all the pages. That may be a clue. Try padding it vertically to test. The only change that I noticed myself was that when it was shorter than the current window it has no scrollbar which caused the positions to shift.