Hi,
So, I had the IE sticking menu items problem.
I noticed that there were two errors about missing files in my console. hoverIntent.js.php and superfish_settings.js.php both complained about missing files on line 2. They were looking for wp-load.php.
I am using an older version of wordpress (2.5) and it turns out that there is no such thing as wp-load.php which the plugin depends on.
So, after some research, I replaced the wp-load.php with wp-blog-header.php and the error disappeared — also, the plugin started working correctly in Internet Explorer.
Hope this helps some of you out there with the IE problem.