sample container error

[Derek Houghton]

 Hi,
Every so often when using the sample container in jetty, when I try and load in 
a new gadget I get the error below. (this is a gadget that has worked perfectly 
well previously)
I'm using v2.0.0.
Relaunching jetty, clearing browser cache has no effect. I cannot load any 
further gadgets.
Help appreciated.

Derek

uncaught exception: [Exception... "Component returned failure code: 0x80460001 
(NS_ERROR_CANNOT_CONVERT_DATA)" nsresult: "0x80460001 
(NS_ERROR_CANNOT_CONVERT_DATA)" location: "JS frame 
::http://localhost:8080/gadgets/js/core:rpc:pubsub:shindig-container.js?c=1&debug=1
 :: makeXhrRequest :: line 4016" data: no]

and line 4016 of the .js:

if (paramData !== null) {
xhr.setRequestHeader('Content-Type', opt_contentType || 
'application/x-www-form-urlencoded');
xhr.send(paramData);
} else {
xhr.send(null);
}
}