Partial Requests (206) on Reverse Proxy Cache

[niwo]

Hi,

we use an nginx reverse proxy cache to serve media file downloads.
An issue we currently have is that for the first uncached requests to
the proxy, nginx is unable to respond to partial-requests and returns
HTTP 200 instead which results in errors for some download clients.

Is there a workaround for this problem? 
- Would it be possible when disabling sendfile or using direct i/o or
forwarding uncached requests directly to the origins and caching in the
background?

Thanks and kind regards,
Nik

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,149469,149469#msg-149469