Lease confirmed, and thank you, Tamara, for extra time ^^
For some "bug report", I've checked the new email sent, and now, the paypal button is working, thanks. The associated link is with the paypal-redirect.cgi, which seems to work, while the associated link of the previous mails was with paypal.com/xclick/ (last mail with xclick was on 10/12/12) I should have reported earlier the exact link with xclick not working (for me), but I guess I forgot.
I'm honestly not sure why the link doesn't work for you. It was my fault that there was a delay applying your payment. I have updated your lease and given you some extra time on it.