Adobe Acrobat and Foxit are free PDF readers. You could try those. Download and install them (you don't need to let them set themselves up to be the default PDF reader for your PC), then right-click on the PDF filename, chose "open with" and select the one you want.
How interesting - there was a billybb asking questions about PDFs back in 2006.
SlackAlice reminded me about cutepdf - I use cutepdf writer (also free) to create PDFs. That might be a good one to try as, if it does manage to read it, you will be able to save it with another name which will be recognised by Preview.
Strange situation, BB. If you've tried several ways of reading it, it very clearly is a corrupt file that JL have sent you; I can't understand them making a fuss about re-sending it.