reload as split screen issue

[Haines Brown]

In my .emacs I have:

  (split-window-horizontally)

so that normal operation (thanks to a wide monitor) is to display two
buffers by default.

However, when I start gnus (M-x gnus) and then view or write a message,
it returns me to a single screen that persists after exiting gnus and I
have to reload emacs to recover the split screen.

I'd like at least to have it return me to a split screen. Better, it
would be nice if gnus were to display the index of messages in one
screen the message itself in the other, and when gnus is closed, the
split screen persists.

Haines Brown