Membership - what am I missing?

The problem I'm having is actually from the Membership plugin ( for some reason it doesn't appear in the plugin list ).

I've been creating membership levels following your manual, however I'm having a problem. I created a new test account and I associate it to one of the membership levels. I can log in with no problems and I access the dashboard. However, when I try to access the main site ( or the posts, pages and wikis sections in the dashboard - but I can see the comments section ) the site takes a very long time to load ( few minutes ) and then the browser gives an error saying that the page has caused to many redirects ( even if the page is redirecting to is the protected page, that I can clearly see when I'm not logged in ). What am I missing?

I don't think the problem are the cookies ( they are enabled ). My memberships are very similar to each other. They use almost all the default settings except for the Associated Role ( I created a new user group that can edit pages ) and the positive rules, which are:
* URL groups ( I created 2 url groups: one with the links of a specific area of the wiki, one with the other ). Only one of the groups is selected;
* downloads
* comments
* pages ( all pages are checked )
* menu ( all the entries are checked )
* more tags ( even if I don't use tags... just to be safe )

Also, is there a way to choose where to redirect the user after he logs in? So I can send my users on a welcome page and not in the Admin panel.

Thanks
Enrico