Hi Nigel,
Thank you very much. I was actually not checking the correct search bar, I am able to replicate this issue. It turns out that it is only due to a misconfiguration of the scrollbar script. There is a separate parameter to disable the mouswheel and the touch-swipe event bubbling to the parent document.
I will include a fix to this in the upcoming release. Until then, if you want, you can fix this manually as well, just follow these instructions:
1. Open up the wp-content/plugins/ajax-search-pro/js/nomin/jquery.ajaxsearchpro.js file on your server
2. Change it’s contents to this, and then save the file.
3. Under the Compatibility settings submenu, change this option to ‘Non-minified’.
4. Clear all layers of site cache.
It may take some time for the cache to clear, but after this change, the scrolling should not affect the parent document now.