Non-breaking spaces with Freefont

[Martin Ellis <m.a.ellis@ncl.ac.uk>]

Anybody using ttf-freefont noticed that non-breaking spaces show as 
rectangles rather than spaces - yet only some of the time?

For example, reading email in KMail is fine, but select some text and 
the rectangles show on lines with some selected text.  Or reading 
news in KNode, rectangles show (in FreeSerif) but not in the fixed 
width (FreeMono) font. Hover a mouse cursor over a Kopete contact, 
and there's one before the status text, etc.

I don't know if this is an issue with the font or whatever package 
deals with font rendering.  I'm running KDE3.2 in sid (but may still 
have the odd experimental package).

Any ideas what's wrong?

Relevant(?) packages:
xserver-xfree8 4.3.0-5
libfreetype6 2.1.7-2
ttf-freefont 20030519-1
libqt3c102-mt 3.2.3-2

Cheers,
Martin