[mythtvnz] Problems reinsalling MythTV 0.21

[james at booths.net.nz]

I just 'upgraded' my Mythbuntu system to 9.10. MythTV 0.22 did not  
work out to well for me (very unstable) so have reverted back to 0.21.  
I followed JYA's instructions for rolling back, however I am having a  
problem with libmyth 0.21-0. When Synaptic tries to install libmyth I  
get:

E: /var/cache/apt/archives/libvdpau0_0.2-0ubuntu11_i386.deb: trying to  
overwrite '/usr/lib/libvdpau_trace.so', which is also in package  
nvidia-185-libvdpau 0

I seem to be stuck in dependency hell. The conflict seems to be  
between JYA's libvdpau0 package and Ubunutu's vdpau-driver  
installation. Trying to uninstall conflicting packages just seems to  
lead me in circles. Can anyone offer advice?