Mail: POP backend crashed with AttributeError in __init__()

mail.py crashes when configured with a POP account. Works perfectly well with GMail though.

ProblemType: Crash
DistroRelease: Ubuntu 10.04
Package: awn-applets-python-core 0.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-20.29-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-20-generic x86_64
Architecture: amd64
Date: Mon Apr 12 20:40:04 2010
ExecutablePath: /usr/share/avant-window-navigator/applets/mail/mail.py
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
InterpreterPath: /usr/bin/python2.6
PackageArchitecture: all
ProcCmdline: python /usr/share/avant-window-navigator/applets/mail/mail.py --uid=1271089447 --window=31457332 --panel-id=1
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.utf8
 SHELL=/bin/zsh
PythonArgs: ['/usr/share/avant-window-navigator/applets/mail/mail.py', '--uid=1271089447', '--window=31457332', '--panel-id=1']
SourcePackage: awn-extras-applets
Title: mail.py crashed with AttributeError in __init__()
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

Traceback (most recent call last):
  File "/usr/share/avant-window-navigator/applets/mail/mail.py", line 491, in onsubmit
    t["callback"](t["widgets"], self.__parent.awn))
  File "/usr/share/avant-window-navigator/applets/mail/mail.py", line 122, in perform_login
    self.mail = self.back(key) # Login
  File "/usr/share/avant-window-navigator/applets/mail/mail.py", line 731, in __init__
    if not self.key.attrs.has_key("username"):
AttributeError: POP instance has no attribute 'key'