Can someone please help me with text message alerts

[jtravapd]

Hello, everyone, I hope someone here can help me because I have tried everywhere with no luck. I have jailbroken my first iphone and my current 3g iphone every time a new version comes out. I currently have 2.1 jailbroken with my 3g phone. Everything works fine except one thing that annoys the hell out of me. Since I have jailbroken my phone, whenever someone sends me a MMS I no longer receive the text message that tells me, "you have received a MMS, to view this message go to att.com, enter XXXXXX passord, login, ect. I know this is annoying in itself, but for some reason, I dont even get the text and have no idea why. Does anyone have any ideas? anyone know why this happens after jailbreak?...it happens with 2.0 and higher on every version. If someone sends me a MMS text i get nothing. I would atleast like to know that someone tried to send me one, then not know i got one...any help would be greatly appreciated...thanks..