Wirelessly posted

Hola!! My phone is really giving me a lot of problems lately:
1. I downloaded Pandora and it gives me the download complete message, I check for the Pandora icon and its not there(it does show up in my applications though)
2. T can't play the videos I record ON my phone or videos I want to watch. I get this: media isn't supported message
3. I changed plans a few months ago and this new plan came with this mms thing. Is this the reason why I can't do any of the previous things in 2? The sprint techies are of no help and I'm pissed I can't even watch videos on here( one of the reasons I turned in my old BB)

Any ideas?? Thanks ;)