I frequently encounter this problem and here is what I do.
1) I take a snapshot of the PDF page I'm interested in posting. (Not the whole PDF)
2) When viewing it on the desktop, I crop out everything that is not relative to the message I'm trying to convey.
*3) I save the cropped version to my desktop in JPEG form.
4) I go back to TF, check Attach Images, browse & select the JPEG from my desktop. I then click on Update file and submit.
Repeat the process if more than one page of the PDF is to be submitted.
I'm sure there are numerous other ways to do this but that's how I do it. My computer is an iMac.
(Example) This is a page from a Furuno PDF:
-- Edited by SeaHorse II on Wednesday 8th of June 2011 11:36:36 AM