You can configure your paypal account to send back the phone number. It won't by default. You can update that from the seller's profile.
You can find this under 'Website Preferences' in your PayPal account's profile.
The direct link to this page is https://www.paypal.com/cgi-bin/customerprofileweb?cmd=_profile-website-payments.
I'd have to look at the page referenced in the errors to debug it. If you send me those pages I'll take a look.