Superfish Supersubs breaks Drupal Behaviors with multiple superfish menu items in block

When I have 2 superfish menus in blocks and the supersubs plugin applied to one of the menus I end up with an issue where the clientWidth of the sf-navbar > li > ul children is undefined. The menu that has supersubs did not have any children so I just turned the plugin off and all is well. The lines of code in question are in supersubs.js on lines 38 and 39 as of Supersubs v0.3b. This issue prevents Drupal Behaviors from executing, though I am not sure why.

size = fontsize.attr('style','padding:0;position:absolute;top:-99999em;width:auto;').appendTo($$)[0].clientWidth;