gnus-group-split confusion

[Keith]

Hi,

This is my first post to the group, so please bear with me.

I have been using Gnus for only a short while.

emacs-version:
  GNU Emacs 22.0.95.1 (x86_64-pc-linux-gnu, GTK+ Version 2.8.20) of
  2007-03-02 on excelsior, modified by Debian

gnus-version:
  Gnus v5.11

I use fetchmail to get my mail from Gmail. All goes well. I it
delivered to /var/mail, Gnus reads it, but dumps much of it in a group
called `gnus-group-split' (don't laugh :-) ). 

I think this is because I am confused about setting
`nnmail-split-methods' and how to set the group parameters. I set the
variables through Customize.

The name I enter is 
    gnus-group-split
The regexp is empty as per "The last element should always have "" as
    the regexp."

Could anyone give me some pointers on what to look for here, or where
to look?

Thanks,
Keith