Question marks instead of apostrophes

[Curt Daugaard <cld@core.com>]

Can anyone explain why Netscape (4.78, running on Sid) displays some
pages with question marks substituted for apostrophes (and maybe for one
or two other characters)?  E.g.

   
   You?ll want to start by assembling three rows of planks
   together. Since the flooring "floats" ? it?s attached only
   to itself, not to the subfloor ? having three rows of
   planks assembled gives you a wide section of flooring to
   move around and adjust until you have everything
   straight. Use 1/4" shims between the planks and the wall
   to provide an expansion and contraction joint ? the gap
   will be hidden by your base molding ? and also to
   wedge the first sections of planking in place while you
   get going.

Any ideas?  

Thanks.

Curt
cld@core.com