Help with chmod

["biscut" <biscut ntlworld com>]

I seem to be having a problem with chmod, whenever I try to set chmod 777
<file-name> then the file permissions never seem to change, i.e they stay as

-rwxr-xr-x readme.txt

if I try to chmod on a directory then I keep getting operation not permitted
errors even though I am root, I get operation not permitted errors if I try
to use chown as well, has anyone got any idea's why this could be happening
please ?? I have looked at man chmod but that doesnt seem to give me any
clues as to why this is happening.

thanks for any help

Regards
biscut