Paypal error “This payment attempt is already processed”

Paypal error "This payment attempt is already processed"

I am using both paypal and e-junkie's "add to cart" buttons on my various
websites:
please view the screen shot linked below displaying error codes that
customers are receiving when checking out on the above listed sites. The
screen shot is from using a paypal account to check out of the shopping
cart. When customers use their paypal account, they are able to login,
select payment method, but then when they click "Pay Now", the page
refreshes with the error message "This payment attempt is already
processed" which you can see on the screenshot. At this point, the "Pay
Now" buttons are grey and not active. However, it seems payments are able
to go through when people use their paypal login despite the error
message.
After doing some research online I made sure that my selling settings were
set to allow transactions changed my primary email on the paypal account
and even created a new paypal merchant account. Still the issue persisted.
Further researching the problem online, I found another question posted
today here on SO with a similar issue: Paypal sandbox accounts gives "This
payment attempt is already processed" error and found the suggestion to
refresh the browser cache and cookies. After completing this I was
delighted to find that the issue was resolved. I then tried other browsers
and found the same fix worked.
My question is now this: is there anything I can do on my end to make sure
my customers do not have to refresh their cache and cookies in order to
use my shopping cart? I spoke with someone last night at paypal and they
gave me an email address to send this information and screenshot to. They
also explained that other merchants were having similar problems due to a
recent system upgrade that paypal has been performing. Whatever the
problem I am VERY anxious to fix it asap.