
Despite fixing the SMS security risk with the latest 3.0.1 firmware, it seems that there is yet another security risk with the iPhone, this time involving your precious email.
It seems that if you search for a deleted message's subject line in Spotlight, it will show up, though it will take several attempts to actually view the content of the message. This may leave the content of the email messages vulnerable to hackers and thieves, or just those significant others that may check for incriminating emails.
But word is that the upcoming 3.1 firmware will patch this up. In the meantime, you can try rebooting the phone, loading messages several times or just simply waiting.