As to your sms issues could you please try an app in the Play Store called GoSMSPro or even Handcent. They're free and have a lots of features that are helpful in sending an receiving files. The stock App is alright yet the features of GoSMSPro or Handcent extend the Android Text Messaging to better and to me more fun....Oh not to forget the 'Emojicons' there are so many to choose from.
They have good features for texting, photos and videos. Great for cross platforms like Android and iPhones.
One last thought the files you are sending are they Jpeg, Png, Mov, Avi there are some files that do not transfer well. Just wondering.
Hope that helps you out.