Comment 8 for bug 1009436

This is probably caused by the following cntlm bug:

http://sourceforge.net/tracker/?func=detail&aid=3512077&group_id=197861&atid=963162

It can be seen by the network traffic that package-data-downloader (through urllib) is using HTTP/1.0, the whole file is transfered and then the connection hangs. See the bug report for more details.

It is fixed in cntlm 0.93beta3 (supposedly).

As a workaround you could try to use proxychains chained "in front" of cntlm (untested).