iDisplayStart is empty in request.GET (def paging())

I used the basic example to try and implement DataTables

https://pypi.python.org/pypi/sqlalchemy-datatables/0.1.6

Everything was working fine when suddenly I clicked on the refresh button and I got this error. Ever since then I can't run the example. I've read up a little about iDisplayStart, but I still don't understand how it has become a problem suddenly.

I'm working on the pyramid framework with python and jinja2( not using jinja2 with anything related to the DataTables example but thought i'd throw it in there.) Will post code if needed