Receiving messages from other networks on my Sprint phone.?

[Richard]

I am and have been with Sprint for several years. What I would like to know from anyone who is with Sprint as well, is has anyone ever had problems receiving messages from people from other networks, altel, at&t, verizon, that have sound as well as movement to it. Such as mpeg messages. I can recieve them from anyone on the Sprint network with no problem, but if any of my friends on other networks send something like that ot me, I can get the sound and a "still" picture, but it will not have the animation. I have called the local sprint office about the issue, but I think these techs here at my local store do not know too much about this. Please help if you have any suggestions or advice. BTW, my current phone is the HTC Hero, but this has been happening since before I had a smart phone. My contract is up, so I can upgrade if I want or need to and I've been wanting the Evo, awesome phone!! But I don't want to pay that much for a phone if I'm going to have the same issue. Awaiting some helpful info please, thanks! If you need to know anything else to get better help, just let me know and I'll add on.