i wish i had more experience with proxy support in libcurl, the library i use to handle the network communication and proxy. what i can do is try to update the libcurl build and see if that has any effect.
I see the error is 407 which has to do with proxy authentication, and i see some comments about getting libcurl to handle such a case, so i'll look into it. maybe email me ([email protected]
donationcoder.com) so i can send you a test build.