Mark,
To me, the problem looks like you may not have the en_GB locale set up and configured. There's some info on this in the perllocale(1p) man page.
Thanks, that man page has helped greatly. I can see that LC_ALL is an environmental variable and I have reset it in a terminal to en_GB, following the instructions for a 'temporary fix'.
If it does not persist after restarting (which presumably, being temporary, it will not) then I will need to discover how to make it so. There is a section on permanent fixes but at the moment I cannot follow it.
Any suggestions for reading on environmental variables will be helpful - I tried 'man environment' as a wild guess :)
How you correct it on Mandrake, I'm not sure.
The irritating thing is that It has only occurred after a re-install (which I have done several times after variously breaking things that I could not fix). Why this install should have given a different result than the previous one is beyond me.
Syd