How do i Enable push notifications on iPod 4G after stupidly disabling them

I have an iPod 4g and I accidentally disabled my push notifications on twitter when the option was offered. Now I want them back. I have tried: resetting location/ privacy, resetting all settings, restoring my iPod, deleteing the app and manually changing the time 24+ hours in advance several times, I have enabled the document & data option( useless). I'm literally at a loss here. Please help.