Why the heck is my URL not decoding when I click it?!!?

Here’s my strange problem. Forgive me if I use the wrong terminology – I’m not a developer.

I have a wordpress blog that’s integrated with amember. I recently installed a WP plugin called AMprotect that will help protect my content.

I post in WP, and the plugin protects certain posts and also creates a line that says “please login or register to view this content”.

When I click the “login” link it takes me to a 404 error. It’s getting a URL like this:

http://www.handmaderesults.com/members/login.php?amember_redirect_url=http%3A%2F%2Fwww.handmaderesults.com%2F1338%2Fhow-to-sell-on-eba%2F

That should be taking me to the login page which then goes on to the proper URL.

When I change the URL to…

http://www.handmaderesults.com/members/login.php?amember_redirect_url=http://www.handmaderesults.com/how-to-sell-on-eba/

I get taken to the post page but no login page between.

I’ve been in touch with the developer and he can’t see what could be doing it. It’s nothing in the .htaccess file, and deactivating plugins makes no difference either. I can see that it’s working properly on other sites, and the URL is decoding properly.

Anyone know what’s going wrong?