andyesk, I'm not sure why you are not recording in Cakewalk instead of the Creative recorder.
At any rate... from what you wrote, I gather that you have recorded with the Creative recorder
and imported (inserted) the audio file into Cakewalk. That's ok to do, though you should
be able to do all of that within Cakewalk. I'm using Pro Audio 9 but it should be the same.
Check the following.....
Make sure you have audio in your project. Sometimes folks get confused as to MIDI vs. Audio. If you're trying to mixdown Audio and all that is there is MIDI you will get that error message.
Also, double click on the track. I believe this will turn the background black behind the
track you selected. I'm not sure if this is required but it's what I always do.
I have an SB Live as well. What I do to record my MIDI into audio is a little different than
what you will probably do. I use an external sound module because the sounds blow
away any soundfonts I've heard. I set my audio track to record the SB line in.
Then I also go into the SB Live Mixer and set it to record Line In. I arm the audio track for
record and begin recording. I recommend you check ou t this FAQ at CW's site:
http://www.cakewalk.com/Support/faq.htm#28
Good luck.....