file removal problem

[R Kimber]

After today's update, my machine crashed on reboot and a few graphics
files are screwed up.  How do I remove them?  I've tried from root but
I get 'Operation not permitted'. The files are:-

cr-x-wS--- 44040 2262871048 2899800918 37, 234 2061-06-17 08:11
areas2.png

l-w-rw---T 44251 1904258270 2899942416 10922 2061-12-01 12:13 word.gif

a third file, word.png, is listed by ls in the directory,
but ls -l word.png gives

ls: word.png: Input/output error

Any help gratefully received.
- Richard
-- 
Richard Kimber
http://www.psr.keele.ac.uk/