Glad you were able to solve it.
In mojoPortal all the editors are set to use 100% width of the container div they live in. Height can be adjusted in module settings for some editors.
As you found it was really the toolbar graphics which would not wrap until you modified the css.
I wonder if we should make this change in all the skins when we have time or just make a note about this in the skinning section.
With these changes does it still look as it did before in wider containers?