You can try adding Advanced settings on your field traps (Start Field On and End Field On).
Also you may check out the "Use legacy PDF engine" if it's an alignment issue, it's in the Home > Advanced > PDF
If that doesn't work, Is there any difference on the format of the block between large and small files?
You can paste an image here for better analysis.
The issue with my Project and Model arose from the fact that the vendor had also changed the dimensions of the output page from 8.5 x 11 to an output page 10.42 x 13.47. The model we had been using we also discovered had flaws that required manual intervention. This morning I had the opportunity to share a WebEx session with Olly Bond who was gracious and generous with his time (after work in Munich) to help me solve my model issues and also provide several enhancements to my process……Basically we redesign the model. I am very grateful to the Forum, Olly and others who provided assistance in resolving this issue.