Open invites

I have no restrictions on who may challenge me, yet when I go to open invites I don't get the 'Accept game offer' even when my prospective opponents parameters don't preclude us playing.
Any Ideas?
Thanx

The person making the open invite can specify what rating he will allow to accept, game by game.[ie, there can be different settings per each game]

You wont see accept game offer becaue you cant play with yourself. Others will see it however.