git-gui push hangs

Hi,

My normal procedure to communicate with GitHub from work is to use
HTTPS. This has always worked fine with the command-line interface:

$ git push
Password: [clickety-clack]
Counting objects: ...

While demonstrating git-gui to a colleague, I added a two-line change,
committed, and clicked Push. I left all the default options (Source
Branch "master" (the only branch), Remote "origin" (the only remote),
and none of the Transfer Options were checked. After clicking Push in
the popup window it was replaced by another window with the expected
"Please wait" message. No password prompt, no new messages, and it
hung for about a minute (CLI feedback is near-instant) before I had to
`kill -KILL` it. It wasn't responding to `kill -TERM`.

After falling back to the CLI and pushing the commit successfully
there, I tried to repeat the GUI operation to see if it would still
fail. Now it got even worse: After clicking Push in the popup window a
new window came up, but the contents were gray and stayed gray.
Another `kill -KILL`, and another try, and this time the second window
didn't even show up. The Push window was closed but git-gui hangs.
Repeated tries get the same result as the last.

git-gui version 0.12.0.64.g89d6
git version 1.7.1

Tcl/Tk version 8.4.19
Aspell 0.60.6, en_US

-- 
Victor Engmark