I'm afraid that the information that you have found regarding having to be registered as a partner is correct. What is you current situation? I am an independent QlikView Consultant and as such can not be a QlikTech Partner, but I got my certification through a partner. Technically I think that this means that I am only certified when I am doing work for that partner - but to all intents and purposes I have passed the certification.
The best bet is probably to ring the office in Leamington and try and speak to someone in the know.
Hope that helps. Feel free to contact me directly if you wish.