Hi Josh,
It should actually work, thank you for letting us know. I checked on your website, and there is a minor syntactical error in one of the script files. Other browsers somehow does not care, but IE fails at that point. I was able to replicate the issue on a local server as well.
If you want to fix it manually for now, then please follow the steps below:
1. Open up the wp-content\plugins\ajax-search-pro\js\nomin\jquery.ajaxsearchpro.js file on your server
2. Replace it’s content with this.
3. Save the file
4. Make sure to have this option set to ‘Non-minified’.
5. Clear all layers of cache.
Once the cache is cleared, it should start working again. I will make sure to include this fix in the upcoming release of course.