I've noticed that when I do a select all (<ctrl>+A), copy, then go to a new page and paste, the resulting shape indices are incorrect.
The shapes on the originating page are simple rectangles and dynamic connectors. All shapes have field inserted shape names, e.g., sheet.3, dynamic connector.5. After pasting, both a connector and a rectangle may have same suffix, e.g., dynamic connector.7 and sheet.7. That's just wrong!!! It creates problems for code.