[ILUG] Corrupt group file

[Karl Monaghan]

I'm after fecking up my groups file (that'll teach me to mess around with
stuff) on my redhat 6.2 box and a search on google hasn't yielded any gems
of inspiration.
I know there is a problem with it 'cause when I try and run locate it says
that it cannot find the group slocate (check and it's in the file) or the
group file is corrupt.
So is there anyway of fixing it?  I've tried copying the group file from the
RH cd and adding the slocate group using groupadd -r slocate but it still
complains.
and ideas? Or do I resort to the windows method of format and reinstall?
(not *too* onerious as I only installed it yesterday.)

Karl.