The iPhone DevTeam just released another update to redsn0w which comes to version 0.9.5b5-5. Some users were unable to send and receive MMS messages, and if you are one of them, here is your fix.
To use this version of redsn0w, and fix your issues, all you need to do is to re-run the tool over your existing jailbreak. If you do that, make sure you don’t install Cydia again. Just de-select Cydia when you will be asked what packages you want to install. If you don’t know how to use redsn0w, you can check out out tutorial here.
Download redsn0w 0.9.5b5-5: