Liferay diaries: Help! My form post parameters are empty!

While hacking a Spring & Liferay prototype, I'm suddenly wondering about why during a form submission there are no parameters (not even empty or null) submitted by the form.

Turns out that I got bitten once more by the two phases of the portlet lifecycle [1] and naivly were handling form submission in the handleRenderRequest method of my controller, whereas what I really meant to say was handleActionRequest.

[1] http://www.liferay.com/documentation/liferay-portal/6.0/development/-/ai/understanding-the-two-phases-of-portlet-execution;jsessionid=6429FCDC126C0864118C99B17CBCDFA2.node-2