Adding more than one flexbox crashes everything

[jessekahner]

I used fix #33 to remove the error mentioned in #32. (I have more than one flexbox)

But by doing so, when loading the page, the browser completely crashes on me (Chrome, Firefox and IE9).

Here is part of my css to help you understand:

#h-wrapper #primary-nav ul.menu {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-box;
  display: box;
  width: 100%;
  padding: 0;
}
#h-wrapper #primary-nav ul.menu li {
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  -ms-box-flex: 1;
  box-flex: 1;
  position: relative;
  line-height: 60px;
}
...
#h-wrapper #primary-nav ul.menu li ul.sub-menu {
  left: 0;
  display: -webkit-box;
  display: -moz-box;
  display: -ms-box;
  display: box;
  *zoom: 1;
  max-width: 980px;
  _width: 980px;
  padding-left: 0;
  padding-right: 0;
  margin-left: auto;
  margin-right: auto;
  height: auto;
}
...
#h-wrapper #primary-nav ul.menu li ul.sub-menu li {
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  -ms-box-flex: 1;
  box-flex: 1;
  line-height: normal;
  border-right: 1px solid #b4b4b4 !important;
}

Any ideas on how to deal with this would be appreciated!