SoundCloud Please Help!

I can only only upload single tracks! Sets are impossible it freezes too often to upload one!! & it still takes at least 5-6 attempts to upload a single track!!!

& then when a track finally uploads, I get this message "Ooops can't upload this track! Are you sure its the right type of file" It does this to mp3's!!!

Why is this happening? Whats goin on???

Its just so annoying to have to go through this shit! Every time I want to upload a track!!!