Events+ Facebook & twitter login.

On my site the Facebook and Twitter logins do not seem to be working.

We have taken 2 orders so far with no problems however not sure which method was used to log in with these.

A customer has just informed me that she cannot login with FB which I have tried and can confirm.

We have 2 payment methods - the other taken 10 orders in the same time, I am now concerned this feature has not been working at all and potentially lost business.
Please can you help ASAP.