Let me share my experiences, after installing gstreamer0.10-ffmpeg_0.10.9-2maemo2_armel.deb the outgoing video started to work but incoming video stopped from working.

But when I did: dpkg -P gstreamer0.10-ffmpeg

then both incoming and outgoing videos started to work fine, so my guess is that installing and then uninstalling ffmpeg package fixes some directory permissions, codec registrations or something, and afterwards everything starts to work.

regards, Jonni
Happy global vanilla 001 PR1.3 user with working in/out google video talk.