Thanks so much for the info

I am teaching in a university under OPT (will expire on 8/1/05). I intend to make my H1B effective from 8/2/05. Can I file the I-129 petition now or do I have to wait till 04/05 to file? Would the petition be refused if I don't go with the istrcution "file as soon as possible but nor more than 4 months before the intended starting date...". Any more advices? Thanks so much