I just installed firebug (never used it before).
All I can see is this error message:
POST
http://tablsorter.appspot.com/dxx 405 Method Not Allowed
--> this is the url that returns the json dataResponse: None
Response Headers
Content-Type text/html
Allow GET
Set-Cookie webpy_session_id=70082469d07d12dc8c875bcbcfa93a87ddcb7918; Path=/
Content-Encoding gzip
Vary Accept-Encoding
Date Mon, 22 Aug 2011 03:49:41 GMT
Server Google Frontend
Cache-Control private
Content-Length 24
Request Headers
Host tablsorter.appspot.com
User-Agent Mozilla/5.0 (Windows NT 6.1; rv:6.0) Gecko/20100101 Firefox/6.0
Accept application/json, text/javascript, */*; q=0.01
Accept-Language en-us,en;q=0.5
Accept-Encoding gzip, deflate
Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7
Connection keep-alive
X-Requested-With XMLHttpRequest
Referer
http://tablsorter.appspot.com/static/demo/dgdemo.htmlCookie webpy_session_id=70082469d07d12dc8c875bcbcfa93a87ddcb7918