Doesn't seem to work in IE7

Hi,

In Firefox this module works fine, but in Internet Explorer, there are some critical problems:

A) I log in as a usual authenticated user and go a given node using IE7. Immediately at the borrom of my IE7 browser, there is an Error notification that reads:
Line 354
Char: 34
Error: Object doesn't support this property or method
Code: 0
URL: http://example.com/path-to-this-node

I type in a tag name *food* and click "Add" -- Nothing happens!
I type in a tag name *food* and press Enter -- the page reloads with the following result:
In "My tags" there's no new tag, while under the "All tags" there is now a new entry that reads:
function(o){for(var i=0,len=this.length;i<len;++i){if(this[i]==o)return i;} return-1;} food