Errors burning cdi images

[turbana]

Hi guys,
I'm presently using DJ4 to burn cdi images with a Yamaha 40x burner, but keep creating coasters.
If I burn using the default settings, then I get the following:
"Buffer underrun or write error".
If I go to the "Advance" tab and select "TAO write",
then I get following error:
"Invalid mode for this track or invalid packet size".

Any ideas on what I'm doing wrong, or what settings I should choose?
Thanks