far as I can tell you have gold account ?
yet they do not allow chunking
second chunk returns 403 forbidden
Code:
HTTP/1.1 403 Forbidden
....
Guest-Limit: IP connections
they claim you're a guest which is 'free' download.
if your gold I would email there support and ask why you can't download with chunks.
if your using free account, I did quick review of the plugin account services and tidied it up.
raztoki
ps. also fixed k2s out of traffic issue also, which was throwing plugin defects in your logs.