Icesfluffy - the letter I got for the PCC re-dos said that I could be exempted from providing a new FBI record if I could show that I had not been to the US since 2010 (date of my last visit, my app was submitted Feb 2011).
What I did was:
1) Copy all the pages in my passport with entry stamps from the US and Jamaica,
2) Then I did a cover sheet with a timeline showing that all the entry stamps to the US corresponded to an entry stamp to Jamaica a few days/weeks later, and that the last one shown was dated in 2010.
3) I cross-referenced the cover-sheet to all the copied passport pages, so #1 on the timeline had a corresponding #1 next to the stamp on the passport page.
4) At the end of the cover sheet, I then requested that they exempt me from the requirement to provide a new FBI certificate, as I had demonstrated that I was in compliance with the condition they had given me for the exemption.
They obviously accepted that, because they made no further mention of the FBI certificate. I hope that helps.
