IE9 Locking width of content after side opens

I have a big problem with IE9 locking the width of the content section after a side panel is opened and closed.

I tried #106 with no luck.

Any idea why the content section would lose it's fluid nature on IE9 once a panel was opened?

No js errors in the console.

Start by reproducing the IE9 behavior described here: open and close a side panel and check whether the content section keeps its fluid width. Review issue #106 for the attempted workaround; done means the content width remains fluid after the panel is closed without introducing JavaScript errors.

Written by the indexing model from the issue text.