Login redirect error

When I have a category as only visible for registered users, and a guest clicks a link to that category, he/she is not redirected to login/register page, but the page gives an error. I have checked all the settings, global site registration is to no and in cb to yes. Loginform is published, registration link is made. I have no idea where to look.
Any suggestions?

System
Mysql 5.0.84
PHP 5.2.9
Joomla 2.5.0 Stable
CB 1.7.1

CB Subs not yet installed, first testing system.

BTW, the php safe mode is set to OFF.

I also found this post by Krilion as a reply to an issue from another user, which is quite similar.

Have reviewed your issue and it's due to the Joomla content categories having a custom accesslevel. The way Joomla sees it is if you don't have that accesslevel then those categories don't even exist for you. Seams wrong for Joomla to show a 404 error instead of redirecting to some sort of error page, but seams just is how it behaves. Once I set the categories to "Public" it works perfectly fine and asks the user to subscribe. Please also confirm if is behaving as expected.

This doesn't make any sense to me. If I can't set the category to registered, what do I set to registered users only? If I only set the content (article and modules) to registered, it does show the page, only without content.

And what could the error be, that I don't get a joomla error page?

It's working as intended. For security reasons if a user doesn't have access then the page acts as if it doesn't exist. After further thought this is good practice on Joomlas part. Again, this is all Joomlas doing and not CB or CBSubs. If you want CBSubs to take over access permissions just set it as Public, protect it with a Plan, and it'll take over.