Push notifications work everywhere but my home network I have an 2G (MC Model) 8GB iPod Touch on iOS 4.0 that has a strange issue.  Push notifications used to work just fine, but for the past month or two, I don't get any notifications while I'm on my home wifi network.  If I connect my iPod to any other wifi network (open private, public hotspot, etc), I get flooded with all the past notifications.  I have tried restoring my iPod numerous times, tried downgrading to 3.1.2, tried different combinations of DNS servers (as mentioned on the net), but nothing works.  Any ideas on how to go about getting push to work when I'm at home?
Your push-port (5223) could've been closed. Try to open it in the router-interface.