[CentOS] "Could not find mime-type"

Tue May 13 16:29:02 UTC 2008
Anne Wilson <cannewilson at googlemail.com>

After a two-week holiday I've just updated my server.  I have a message from 
kcontrol - "Could not find mime type application/octet-stream".  A .png 
thumbnail on the desktop isn't displaying, but apart from that I don't have 
much of a clue what has happened.  Nothing seems to appear in messages.  Any 
help, please?