abrt version: 1.1.14
architecture: i686
cmdline: python /usr/bin/pitivi
component: pitivi
executable: /usr/bin/pitivi
kernel: 2.6.35.10-74.fc14.i686
package: pitivi-0.13.5-4.fc14
reason: stream.py:327:get_stream_for_caps:AttributeError: 'NoneType' object has no attribute 'to_string'
release: Fedora release 14 (Laughlin)
time: 1293898130
uid: 500

backtrace
-----
stream.py:327:get_stream_for_caps:AttributeError: 'NoneType' object has no attribute 'to_string'

Traceback (most recent call last):
  File "/usr/share/pitivi/python/pitivi/ui/encodingdialog.py", line 147, in _recordButtonClickedCb
    self.addRecordAction()
  File "/usr/share/pitivi/python/pitivi/ui/encodingdialog.py", line 210, in addRecordAction
    self.have_video, self.have_audio)
  File "/usr/share/pitivi/python/pitivi/settings.py", line 605, in export_settings_to_render_settings
    astream = get_stream_for_caps(export.getAudioCaps())
  File "/usr/share/pitivi/python/pitivi/stream.py", line 327, in get_stream_for_caps
    log.debug("stream","caps:%s, pad:%r" % (caps.to_string(), pad))
AttributeError: 'NoneType' object has no attribute 'to_string'

Local variables in innermost frame:
pad: None
caps: None

How to reproduce
-----
1. i was rendering video
2.
3.