Problem with the window size Rated 4 out of 5 stars

Hi!
I love the theme, but I just found out that this add-on is the source of my problem.

The third column in my three-column-view is not showing properly. the horizontal scroll bar is missing and text is just continuing to the east.
See https://getsatisfaction.com/mozilla_messaging/topics/window_size_not_correct_scroll_bar_missing_in_3_column_view?utm_content=reply_link&utm_medium=email&utm_source=reply_notification#reply_8235808

Thanks!