Won't let me Press A to Continue

I had the same problem, was speaking in passing to one of the lads i work with, basically all you need to do is go into settings, network settings, advanced settings, alternate mac address and press clear, should give you a message about requiring a restart, let it do its thing, then Bobs your uncle, Fannies your aunt and you can load the game and pressing A lets you sign in and start playing. Hope this works for you, worked for me.