Hammering the buttons? Well I just tried it a few times myself and it doesn't work, I didn't think it would either.

I have tried deleting the installation from the HD and playing from the disc.
Moving my saves between USB and HD.
Loading much earlier saves and playing up to that point again.
But all end up not working no matter what I do the game just hangs shortly after the summoning begins.

It's definetely a glitch and I expect more people will encounter it as time goes on and they reach that point in the game. The only way around it that I can see is if a patch is released.

What I can't understand is this was supposed to be all sorted with this new release but it is clear from these forums that there are still numerous bugs in the game.

Very frustrating.