I want to use Commerce Paypal Express Checkout module to process PayPal payments, but I am getting the following JS error in Firefox web console:

"The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must to be declared in the document or in the transfer protocol."

I've tried setting the character set in my PayPal account to windows-1252 as per the FAQ on the Commerce PayPal page, but it didn't change anything.

Does anybody have any ideas what could be going on?

By the way PayPal WPS works fine, although I would like to implement Express Checkout since it seems PayPal is moving towards Standard/Advanced/Pro in place of WPS/WPP.

Cheers