Best answer by Mathis
Thanks for posting and sorry to hear uploading does not seem to work very stable for you. Hmm, let's see. I can see you've successfully uploaded a new track to your account most recently - have you done any troubleshooting to get this working?
If not so, here's a list of things you can try to either troubleshoot the issue further, or to optimise your browser in general for uploading.
Hope this helps!