And export to IDML should fix the pasteboard size problem unless there is really a stray object out there (see Remove minor corruption by exporting). You can eliminate any stray objects by going to the page, doing a Select All, then hold Shift key and use the Select tool (black arrow) to drag around the perimeter of the page (and any objects you want to keep that are on the pasteboard), then press backspace or Delete.
The two odd spreads have shuffling disabled....
As soon as you mention shuffling, I remembered.
No luck with the stray objects/ IDML export. Oh well!
- Create a new Spread after the problematic spread.
- Select on the old spread everything with the selection tool. Don't use the select all command.
- Drag all selected to the new spread.
- Delete the old spread.