Bump! Are there any recommendations from Episerver in this matter? Surely there are more sites out there that use asynchronous calls that needs to be working in editmode?

We had the same issue today... What you need to do is force the URL to be the public-facing (non Edit Mode) URL.

Knowing this, you'll find this topic: http://world.episerver.com/Modules/Forum/Pages/Thread.aspx?id=66580)... which states there is a bug (#91931) that prevents this. This bug was fixed, but is not available until (hopefully) EPiServer 7.5 (see comments in http://world.episerver.com/Articles/Items/EPiServer-7---Patch-3/)

The current workaround is this code, which we put outside of the controller in a static class:

public static string GetPublicUrl(ContentReference contentLink, string language, RouteValueDictionary routeValues = null)
{
    RequestContext requestContext = new RequestContext();
    requestContext.RouteData = new RouteData();

    requestContext.RouteData.DataTokens.Add("contextmode", ContextMode.Default);

    if (routeValues == null)
    {
        routeValues = new RouteValueDictionary();
    }

    var urlResolver = new UrlResolver();
    var contextSaved = HttpContext.Current;
    HttpContext.Current = null;

    var url = urlResolver.GetVirtualPath(contentLink, language, routeValues, requestContext).GetUrl();

    HttpContext.Current = contextSaved;

    return url;
}