burning dvd on mythtv

[norman]

I want to transfer a recorded TV broadcast to a DVD in Mythtv which I
have done many times but not for about a year. I went through the usual
menus and the preparation for burning commenced. All went well,
dvdauthor was well on its way when an error message appeared and
processing stopped. The message was to the effect that /dev/dvd could
not be found. I know that I have updated the OS and now run Ubuntu 8.10
so could something have changed of which I am unaware? Please could
someone offer me some useful guidance.

Norman