Following the release of the iPhone OS 3.0, several hackers released tools to jailbreak aux iPhones loaded with this new OS. However, people rapidly notice that the psh function was not working anymore. Unexpectedly, some users started complaining against Apple as they wanted to blaim the company to punishing them for having jailbroken their iPhone According to AppleInsider, the jailbreak is directly responsible of this issue with the push function and due to the modification of the unique identification file of the iPhone. So all iPhone jailbroken with the same tools are missing one ID element used by Apple to identify the iPhone to ensure that the message and/or notifications are being sent to the right unit.
So hackers should go back to the bench and start looking for a fix.