Cannot upload files to isc.org

[TAN BUI]

I have filed a bug report to bind9-bugs at isc.org, ID is [ISC-Bugs #27700].
I was trying to upload the tar files via https://pandora.isc.org/ ;
after getting to the link provided by "ISC Pandora <nobody at isc.org>",
I filled in all the information, selecting all the files to be
"dropped off" and clicking on "Drop Off Files", I got a "400 Bad request" 
page, telling me that:

"Bad Request

Your browser sent a request that this server could not understand "

I am using Mozilla Firefox 8.0 on a Windows 7 machine. I have tried
some more times but always got the same "400 Bad request" page.
I must have done something wrong but don't know what. Is there any
other way I can upload/send the files for reporting the bugs?

Tan