Best answer by Mathis
I just replied on a different topic to this, but just in case - here it is again:
Sorry about the troubles with this. This is due to a bug on SoundCloud's end. Our engineers are already working on a fix for this. In the meantime, you can still change your profile image on the "Edit" mode (by clicking on "Edit" on the right hand side under your banner).
Apologies about the confusion around this.