Certain carriers may allow different message size limits for different devices. If the iPhone is on a different network and is allowed to send a message of incompatible format or size this type of issue may occur. This is common especially when MMS’ are coming from iPhone devices and cross carrier.
Some third party applications such as handcent or chomp SMS may translate iPhone messages correctly. In fact I have seen some settings in those applications that change the message type to iPhone specific.
The best recommendation is of course to use E-Mail to send and receive messages. With the integrated address book and sharing from the gallery this is almost as easy as MMS and has a couple of advantages.
- Doesn't compress or make your image smaller
- Easier to store or access from a computer
- No compatibility issues
Hope this helps!