Broken Activation Page

Hi guys,

im experiencing a strange problem with blog activations. When a user clicks on activation link in the email he gets a blank/broken page with no password/login details. No follow-up email is also sent.

When that link is clicked the second time - it says that the blog is already active.

So the user has to go to Lost Password page to get new passowrd in order to log in to the blog.

Can anyone help pls?