If you find IC to be good for you please stay there as it's your phone so you know what is best for you.
However here is a Messaging.apk .zip that I bet fixes your issues. ;)
I was having issues with the group MMS also. But with this zip e...
updated the firmware and installed V4.01 and mod pack without selecting big photo. TI restored most of my data. So far everything is running smooth and no errors. Thanks Andy!!!!!