NOTE: I\'m not working at the company where I worked when I posted this question, therefore, even though some great answers might come in, I won\'t act
A definite solution for some getting -1004 on older Samsung phones:
In my case, I'm using a Samsung Galaxy Pocket and had a mp3 file on our CDN, which wouldn't play, i.e.
http://domain/path/audiofile
When downloading the file to the phone, however, it plays in the native player. Not in my app and not in browsers, though. Turns out, the media player service needed a file extension to hint the media type and couldn't auto-detect based on file headers.
I solved it by giving the file location an actual extension.
http://domain/path/audiofile.mp3
Solution