MMS and Cellular Data not working at all

So I have updated my iphone 3gs to Apple's latest released 4.0 OS, but after making the updates, the MMS button was not being used ever and also the cellular data wouldn't come into work, but the wifi still functioning at all. I have went through the blogs and different forums about this very issue and it assumes as very common but none of them are in situation to provide the sufficient answer that can be helpful for me to solve this , has anybody here who had such type of problem and fixed it ?

You can say, there is something close to this problem that I am getting now , the same thing is going on with me also... I can send and recieve the texts and calls with the proper way and for the rest of the day's that's well gone for me. I just pray to god that someone here could help me out from all of these issues and if any suggestions for my iPhone 4. Please help me !!!!!

With each one serious upgrade on the iPhone specially Jailbroken ones, You should configure up as a new phone and not need to go with the backup. To resolve this issue, you have to just connect your phone with the iTunes, just be sure that you have sync entire songs that you have stored and applications etc. So you have a manual backup then restore to a new one phone and then re-sync all of the stuff back on ( without restoring from backup).

If you need all your saved messages etc I would recommend you to go for the restoration of the 3.1.3 and if you are running with the hashes saved and just hold out for the OS4 jailbreak..

Hey guys! I am also running with the same issue here and not getting any solution on different sites and found something but not working at all. This is also the issue with the cellular data and internet connection. The case were fixed by issuing the valid information within the Settings=>General=>Network=>Cellular Data Network=>Cellular Data =>APN field. The valid data = internet.

I purchased a Unlocked iPhone 3gs from one of my friend which is working on 3.1.3 firmware with 5.12.01 jailbroken with the Spirit and unlocked with Ultrasn0w.

The MMS was playing well yesterday and the day before and suddenly it is not functioning at all. Whenever I try to send the MMS then I found that it would not send, and I am unable to receive any MMS at all . I am on the 34.99 Blackberry Internet Service + Unlimited Text Messaging scheme and it was going well before.

This is my settings configured :
Cellular Data
APN internet2.voicestream.com
Username BLANK
Password BLANK

I don't have any idea what the actual issue is here , but I just needed to tell that you are paying way so much for data. 34.99?? Why? You don't required this a lot ! Downgrade to the web2go 9.99 via your account online for goodness sake! That is just like a maximum cost to pay for the same data on a 9.99 service.