Firefox problem printing big fonts

[Andrea Venturoli]

Hello.

Whenever I try printing from FireFox (mainly to PDF virtual printer, but 
also on paper), I get wrong headers fonts.
I.e. most of the page gets printed properly, but [sub]titles (or any 
bigger text) are just illegible crap.
Of course I see the page correctly on screen, before printing.

How do I go about diagnosing this?
Perhaps I'm missing some font package, but which one?
Or again, is there some setting that must be done (in FireFox? CUPS? 
other?)?
Some tool to check?

Sorry if my question is vague, but I'm lost at where to start looking.

  bye & Thanks
	av.