Try adding useraction=commit in your Express Checkout redirect URL
https://www.paypal.com/cgi-bin/websc...heckout&token=
https://www.paypal.com/cgi-bin/websc...=commit&token=
This will give the buyer the option of paying after they login to their PayPal account. The button will read Pay Now. Currently without useraction=commit the buyer logs in and selects a funding source then they click continue which transfers them back to your website to complete the payment. It appears you are not transferring your buyers back to the correct page to complete the payment. If you have any further questions or concerns about integrating PayPal with your web site, please feel free to contact us again at: 888-221-1161, reply to this ticket, or go to
https://paypal.com/integration
Thank you for choosing PayPal, I wish you the best with your future transactions.