Users cant add more than 1 website

Hi, thanks for this great script, i have installed PIWIK with signup plugin. I have a issue with add more sites for users. All my registerd users cand add more than just 1 site to track. In admin menu i have add website option but the rest of registered users not have this option.
How can i solve that ?
Thanks !

We are building a Paid plugin to do exactly this, please contact us at: http://piwik.org/consulting/#contact-consultant if you are interested!

I am interested for that, i have also a problem with signup plugin, when is enabled, piwik not receiving data from sites, whwn it is disable, piwik receiving data from sites.

Hi! I am interested too in this feature:
please can you explain better to me How it works?
My need is for the possibility of build reports not only for single website but grouped ‘per customer’, who may have more than one site.
Is this the case?

Thank you very much for answering

Simona