My LL gave me an eviction notice....?

Last night (september 1 2009), at 10:00 PM (central) my landlord came to my house that i rent from them and asked if we had the rent. my roommate told her no, not until the 3rd like we always do. She then handed us a piece of paper that was an eviction notice. it said we were being evicted due to breach of tenancy: failure to pay rent. We are not past due on any rent due to them and we have a grace period of til the third. the notice said to either vacate, pay rent or cure the breach within three days from service of notice or she will take legal action to evict me from premises. Is this a legal notice? she showed up AFTER business hours and on the first of the month and only handed this notice to us AFTER we told her that we are paying the rent ON THE THIRD like we have done so for over two years. we have no lease with them anymore. we started out with a year lease back in august 2007, but since haven't had one. we have been renting said residence for over a year, paying them every month. we are NOT behind on rent. what can i do to protect my interest in this matter? she told us last month that she was going to give us a 30 day notice to vacate by the 1st of October and we agreed. this is stressing me out thinking i have to be out by the 3rd of this month. i planned on paying her rent for september so we could have that thirty days.