I have multiple PCs I wish to purchase / donate for.  I donated via PayPal using the same e-mail address as the first for the second machine.  It confused your system.  I received a blank password.  How to fix?  I have multiple PCs I wish to contribute for.  Thank you! 

This happened to me too.  If I remember correctly, what it ended up doing was adding the contribution amount to my existing login.   So instead of $5 total donated it shows up as $10 kind of thing.   I think this worked out better, because the number of licenses was more for $10 than it was for 2 x $5.