This post is slightly geeky and more for my own benefit just in case I come across this problem again and need to fix it.
There is a bug in iPhone OS 3.0 and 3.0.1 that stops push notifications from working when the phone is connected to the internet over wifi. I could only ever receive push notifications when outside my home connected to the cell network. Despite having cell reception in my home the very fact the phone had a wifi connection seemed to kill push.
The solution (and I have no idea why this works) is to manually change the iPhone’s wifi DNS settings to use a public DNS server (like OpenDNS) and not allow it to receive it’s DNS settings from the wireless router.
I changed this setting and the notifications flooded in!
I noticed this issue to and your fix seems to have worked for me. Thanks!
Thnx man. This solved my problem too.. Thumbs up