at a guess i would say that the FREE Joomsef extension - its adding in the"Joomla SEF URLs by Artio" link at the end of the json that is returned to the "add to cart" ajax call.

Jan can you do a test for JRequest::getCmd('format') == 'raw' and if it is not append the url?

I appreciate you want to advertise with your free product but perhaps advertising to a JS script won't gain too many new customers ;)

By the way I got to this thread as I am encountering a similar issue with my component (Fabrik) when artiosef is enabled

At a guess I would say its because artio sef kindly places the "Joomla SEF URLs
by Artio" link in any page request (such as the ajax call I think Yoosearch may make)
In doing so the returned data from the ajax call can't be evaluated and hence your drop down can't be populated

If I could see where/how the link is added I could suggest a fix - a simple test for

if(JRequest::getCmd('format') != 'raw'){
//show link
}

but i can't see where the link is inserted

Can someone fix this bug?