Another DVD Santa Problem!

Hey, I have just started using DVD santa tonight as I was fed up with the crappy looking video I was getting from winavi.
I have just converted a avi to dvd format and at the moment I am getting no picture only sound…this didn’t happen when using Winavi!
I have a whole bunch of codecs on my pc so I dont think that could be the problem, I did run the program through g-spot and it stated that the codec was installed.
Can someone help me before I turn into the Hulk…grrrrrahhhhhhhhhh