Hidden Code and Paypal Create Button code

Hi
Anyone know if there is an issue with copying and pasting in code into WordPress from Paypal create payment button application?

One Paypal tech support agent mentioned there is a problem.

My problem is that the payment button works for most people on my WordPress blog but for some shoppers, in the last month, with a Paypal account they are directed to Paypals log in but are given no details of what they are buying, how much and who to pay once logged in?

Possibly a shopper browser issue? My other wordpress sites payment button works fine.

Any help would be gratefully appreciated.

Thanks