Hi Cynthia,
I am very sorry for your frustration. I do understand that it's more than weary, when you have to face a problem over and over again, and explain it.
I am more than willing to help you out. I have loaded your website in FireFox browser on my Windows desktop. Here's a screencast of my actions:
http://take.ms/H4RqB
I have added a couple of products to bag, cleared the bag, added one more and proceeded to PayPal. I was not able to replicate the issue with green Checkout button, that is displayed instead of PayPal Express Checkout button.
Have you tried to clear the cache and cookies in your browser? Please, do and open your store to check, whether you see PayPal Express Checkout button.
Have you tried to open the store page in another browser on your device?
If you still see the green Checkout one, please open the page
http://www.ecwid.com/internet and make a screenshot of all browser details, that it detects.
We will be investigating the issue further to make sure, that PayPal Express Checkout loads for you successfully.
I am really sorry, that you have to go through the tests and explanations all over again, but this is the only way we can determine the reason of the problem remotely and fix it. Thank you in advance for your cooperation!