AJAX Issue with Ajax.request + JSON

[Mulone]

Hi guys,
I'm making this ajax call:

 url = "/GeoAdaptaApp/geoLogger/logGuiEvents?json="+aLotOfJSONStuff; 
        encUrl = encodeURI(url,"UTF-8");	

    new Ajax.Request(encUrl, { 
           method: 'get', 
           onSuccess: this.sendQueueToServerSuccess( this,logConsole ), 
   	   onFailure: this.sendQueueToServerFailure( this,logConsole ) 
    });

The JSON string seems correct (I checked it with a validator) and it worked on an Ajax.updater (but i need a request now).

Firefox keeps telling me:

Error: no element found
Source File: http://localhost:8080/GeoAdaptaApp/geoLogger/logGuiEvents?json=%7B%22eventsQueue%22:%5B%7B%<JSON stuff>
Line: 1

The call always end up in the onFailure block.

Full request here: http://tinyurl.com/y8oh968

It's very strange, any idea about what it could be? Is there a better way to pass json objects to the server?

Thanks,
Mulone