I think I had the same problem. Ever since updating to Oneiric I hadn't been able to view any videopodcasts (m4v) in Banshee.
Apparently it's related to this bug: https://bugs.launchpad.net/ubuntu/+source/gstreamer0.10/+bug/856988
The solution provided there by user aortega [rm -r ~/.gstreamer-0.10] resolved this for me. :)
I think I had the same problem. Ever since updating to Oneiric I hadn't been able to view any videopodcasts (m4v) in Banshee. /bugs.launchpad .net/ubuntu/ +source/ gstreamer0. 10/+bug/ 856988
Apparently it's related to this bug: https:/
The solution provided there by user aortega [rm -r ~/.gstreamer-0.10] resolved this for me. :)