Wireless Access Point formerly connectable has no WEP,WPA or Mac filters onand I can't connect?

If this is not your access point (in which case your use of it is totally illegal) the owner has probably discovered you using it and set MAC filtering only allowing his known mac addresses. If so you are lucky he did not report it, there is up to 5 years prison for this. If it is yours and you did not set encryption, someone else may have hijacked it and locked you out.