My colleague suggests that texniscope is somehow to blame and that I should try purging it from my system. I really hope not to have to resort to that!
I'm a bit surprised by your problem with MacTeX. I recently installed the 2008 version and it is working like a charm, be it pdftex/latex or xetex/latex. Even with the previous teTeX installed I had, fonts were not a problem. Can you put your foo.tex somewhere for us to test?