add-apt-repository doesn't add key when behind a proxy

Binary package hint: apt

Hi,

I've run into an error while trying to add a PPA repository using add-apt-repository.

Ubuntu Version : 10.04
apt version : 0.7.25.3ubuntu7
(up-to-date at the time of the error/reporting)
I'm behind an HTTP proxy, updating/installing using Synaptic/apt works fine.

Here's what I did and whet happened:

$ sudo add-apt-repository ppa:michael-gruz/ppa
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python2.6/threading.py", line 532, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.6/dist-packages/softwareproperties/ppa.py", line 59, in run
    self.add_ppa_signing_key(self.ppa_path)
  File "/usr/lib/python2.6/dist-packages/softwareproperties/ppa.py", line 88, in add_ppa_signing_key
    print "Error reading %s: %s" % (lp_url, e)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 43: ordinal not in range(128)

This PPA is to install Skype. (we use it at the office...)
I got the line from http://doc.ubuntu-fr.org/skype, the French speaking Ubuntu community site.

After launching the command, the terminal hangs for 10/20 seconds (^C doesn't do anything), then the error message is displayed.
The return code ($?) is 0; but I don't know if it's from sudo or apt.

The result is that the repository is added but not the PGP key.