I'm sure this has been asked before, but none of the Google results specifically mention v4, or the moono skin.
I want to increase the width (and height for that matter) of the pulldown that appears when the user clicks on the "Styles" button. I've seen this page: http://gabesumner.com/modifying-the-width-of-the-ckeditor-styles-dropdown, but I'm unable to get it to work.
Ideally I'd like to be able to configure this through JS, or through CSS that isn't part of the skin file - so I can feel free to upgrade. But, I'll take whatever I can get.

I have the same problem,
I have the same problem,
found another tip
http://stackoverflow.com/questions/13235005/change-the-size-of-the-format-drop-down-menu-in-ckeditor
that also seems to apply to an older version, did not work for me, still looking to solve that.
My Solution
I had the same issue and wished to alter the height too, my solution was to edit editor_gecko.css in skins/moono adding
.cke_panel
{
height: 300px !important;
width: 180px !important;
}
The only issue, this effects all the drop downs.