Metatag tokens cause JS problems in IE9

Hi,

This might be more of a Token issue but since it appeared in Metatag I just thought I should post it here first.
We're having some problems on a rather large site in IE9. Each time we try to add/edit a node that has Metatag support the page takes forever to load and then just becomes unresponsive. Apparently this is caused by JS not being able to load all tokens and making them clickable (over 14000 tokens). This only happens in Internet Explorer 9 - Firefox and Chrome work fine (unfortunatly we can't just say to the client that they need to switch browsers). Is there a way around this problem or are we overlooking something?

thanks!