Cannot get Paypal to function

[SA_Chick]

I have read through the board and no one seems to be having my same issue.

I'm running Joomla 1.0.15 and Virtuemart 1.1.0.

I have gone through every step that is in the sticky note in this section regarding setting up Paypal, and I still cannot get it to work.

I go through the checkout process and once I select the radio button to choose Paypal as my payment method (only other is CC via Authorize.net), once I click "Next" it gives me a 505 error.

"The website cannot display the page
HTTP 500 
   Most likely causes:
The website is under maintenance.
The website has a programming error.

   What you can try:
     Refresh the page.
     Go back to the previous page."

I have emptied my cookies, cache, history, etc and nothing seems to be working. I have all the correct information plugged in, so I'm really frustrated at this point. It was working 150% before I installed the new VM 1.1.0.

The URL when I mouse over the "Next" button doesn't lead to Paypal, it just says "https://www.sourceautomotive.biz/index.php", so I'm not exactly sure what's going on.

If someone could shed some light on my issue, I would really appreciate it.