So I was wanting to do some client-side validation and then call back to the server should the page suddenly have become in/valid, I called Page_ClientValidate from javascript.
This returns a boolean value. It also as a side-affect of setting the Page_BlockSubmit to false should the page is invalid.
Which in turn blocks anything from submitting back to the server.
So to get around this, just set Page_BlockSubmit to false and submitting back to the server works as expected.
Thanks to the forum link!
