[wmii] Ruby wmiirc leaving space on screen without bar

Hi!

I've just noticed that, when using a second monitor with TwinView, my
wmii setup leaves space at the bottom of the screen without the bar.

I'm using the provided ruby wmiirc (with just a few modifications to the
config.yaml) with wmii 3.9.2.  It doesn't happen with the default
wmiirc.

Any pointers for fixing it?

-Adam