I experience the same problem, but only for non validated emails. If the email is validated I can delete the user with no problems though the 'site access' interface.

It also happens that if you try to click on the user, you are redirected to the site access page, not to the user's profile. This again happens only for non validated profiles.

We are being hit hard by spammers and the only option at the moment is to delete the entries directly in the database, which is quite time consuming :(

I can alternatively activate them, and then delete them (everything through the web interface), but I would rather prefer to delete them directly, without them being ever activated into our system.

Does anyone has any idea of why this happens?

Thanks in advance!

The problem is because of outdated site access plugin. If you have the uservalidationbyemail plugin enabled, you can easily remove these users from the admin panel. Dont try to delete the users directly from DB. It will remove only the users. Their contents will remain their in the site and finally the whole site will be broken. Use elgg's way to dlete the user.

not 'outdated site-access' - there is a conditional in the core code that blocks that user delete action - we have s/a working @ v.1.7.8 ;)