Paypal Express loop issue with 1.4.8b on firefox

Im trying to fix this problem on Paypal Express (by Qphoria) for the loop issue with 1.4.8b on firefox my customer are tell me loop problems after sing in on paypal to pay they are send back to Account Login and from Account Login they chose Guest Checkout after they they click continue are send bak to Account Login it just keep on loop
any one knows how to fix it
Let me know
am using opencart 1.4.8.b
Thank you