Pruning the forum database.
how old is the unit? more than 5 years?if you can get a borrowed external dvd burner, this could give us more information here
You would just waste 5 more minutes to make an .iso and then try to burn it to a dvd. Just to be sure. Why don't you want to try that solution?
My first suggestion was to try another burner app because k3b is not the best solution, please try that