AverageRatingControl generates Unexpected number error in javascript with decimal numbers

Hi:

I'm using this code in a SharePoint 2013 webpart in order to show the stars rating for an item, but I'm having a problem with the average Rating format:

                using (SPSite site = new SPSite(SPContext.Current.Site.ID))
                {
                    using (SPWeb web = site.OpenWeb(SPContext.Current.Web.ID))
                    {
                        web.AllowUnsafeUpdates = true;
                        AverageRatingFieldControl PageRatingControl = new AverageRatingFieldControl();

                        PageRatingControl.ID = "RatingCntrl";
                        PageRatingControl.ListId = _contenidoList.ID;
                        PageRatingControl.ControlMode = SPControlMode.Edit;
                        PageRatingControl.FieldName = "AverageRating";

                        PageRatingControl.ItemContext = SPContext.GetContext(HttpContext.Current,
                            item.ID,
                          _contenidoList.ID,
                          web);
                        divRating.Controls.Add(PageRatingControl);
                        web.AllowUnsafeUpdates = false;
                    }
                }

If I look into the script that is injected with this code I found the following:

EnsureScript('SP.UI.Ratings.js', typeof(SP.UI.Reputation), function () {
var avgRating = 3,66666666666667;var ratingCount = '0';var ratings = '';var ratedBy = '';var itemId = 6;var userId = 27921;var listId = '22b81e75-f22d-4c76-8003-13962b016efb';var listTemplate = 'GenericList';var elmCtrl = $get('RatingsCtrl_ctl00_ctl52_g_33e57148_fbe8_401e_bcc8_60548492189a_RatingCntrl');

Uncaught SyntaxError: Unexpected number

If you can see, the avgRating variable is filled with a '3,666666666667' instead of a '3.666666666667' so the script is throwing an exception "Unexpected number". If the average rating is an exact integer, the control works just fine. Is it possible to force a specific culture so it tooks the correct decimal format? Or there is any other way to get around this issue? We are using the Spanish Language Pack. 

Regards,
Gustavo