If verifying means entering a credit card, receiving an sms then I could not say we have done that.

I am not sure what 'registering for mobile' means in the doc you listed? So cant be sure thats the problem either.

basically, although we know you should not do this, we have created some simple accounts on facebook (which we intend to delete after testing) and verified by clicking on the link they send you in the email and thats it. No SMS or credit card thats for sure.

Looking forward to testing after your fix is implemented to see if that is the issue ;-)