I would give Nero a run and see if that helps solve your problem.
Way back in the day you had to do the wav conversion before burning, but this is just not the case anymore, you might actually be chewing up what ram and processor speed you do have by doing the conversions.
Also you may wanna look into
http://www.cdburnerxp.se/ I have a few friends online who have used it and said that it worked very well and were thinking about dropping Nero for it, as it is free software.