poor font rendering in ffox on f18

[Mike Wright]

Hi all,

Running firefox v26.0 on f18 with xfce and trying to enjoy the new Ted 
Talks, e.g.:

http://www.ted.com/talks/juan_enriquez_wants_to_grow_energy.

Their new site pulls in its own fonts: helvetica-neue.

On Chrome it displays perfectly (or falls back to sans-serif???) but on 
firefox it is extremely difficult to read.  Using firebug I can force it 
to use sans-serif, which does display nicely.

Here's the link to a screen capture:

https://dl.dropboxusercontent.com/u/19486401/neue.png

that shows the leading vertical edges of n,u,h,p don't display; x is 
also broken.

Any idea where this bug lies?  ff, f18? and how to force "sans-serif" 
without doing it manually for each ted talk.  Maybe a ted talk on how to 
fix their choice of font ;D

Thanks for any suggestions,
Mike Wright