locale not supported by C library

[Peter Hugosson-Miller <pehu@im.se>]

Since I upgraded from potato to woody, I've started getting _lots_ of 
these warnings in my ~/.gnome-errors file:

Gdk-WARNING **: locale not supported by C library

OK, it's just a warning, but it's new, and I just wonder

 a) If I need to fix it to avoid _real_ problems later
 b) If so, how do I fix it?

I wasn't aware that I changed anything locale-specific during the 
upgrade, apart from the recommended 'apt-get install locales 
util-linux', but I'm fairly sure I just accepted the defaults 
everywhere, so that shouldn't have broken anything.

--
Cheers,

  .~.
  /V\
 // \\
/(   )\
 ^`~´^
< hugge >