(Banshee 1.4.2) GStreamer Resource Error: NotFound

Hi, I just installed the latest banshee on intrepid from the PPA but I'm having a problem getting it to play anything. I have all the necessary gstreamer plugins (rhythmbox and everything else using gstreamer is still working fine) but I'm seeing the following error if I try to play any file in any format:

[Error 23:12:22.749] GStreamer resource error: NotFound

I tried running banshee --debug and noticed the following messages but I don't know if they are relevant or anything to worry about:

[Debug 23:12:17.639] GStreamer pipeline does not run: audioconvert ! xingenc bitrate=128 ! id3v2mux
[Debug 23:12:17.698] GStreamer pipeline does not run: audioconvert ! fluwmaenc bitrate=64000 vbr=false ! fluasfmux
[Debug 23:12:17.698] Extension service started (GStreamerCoreService, 0.176063s)

I'm a bit puzzled because I installed banshee from the same PPA at the same time on my laptop (also intrepid) and that is working fine :S As far as I recall my gstreamer setup is completely default standard. The only difference I can think of between my desktop (broken) and my laptop (fine) are that the former is amd64 and the latter i386. Although my desktop did have a much older banshee on it once before and I noticed when I had a poke around in gconf that there are 3 banshee config keys under apps: banshee, Banshee and banshee-1. Could there be some old settings causing trouble? The Banshee key looks to be for plugins so I guess that's normal but there are many similarities between the banshee and banshee-1 settings.

I couldn't find any other config file for banshee at first glance though I tried purging the package and installing again only to find that it appeared to retain all the same settings, cover art etc. so I'm not sure what to delete/where or whether the problem is something more complicated...would like some advice on the error please before I try anything further, thanks!