AFAIK, usually when the buffer is empty you get what, in strictly technical jargon, is known as "coaster", and not just a click in the audio CD... most software will interrupt the writing if "buffer underrun" occurs...
i havent heard of any problems so far but when burnproff hits an empty buffer it stops writing and waits till the buffer recieves more data then returns to the exact spot that it halted and begins writing again so coasters are a thing of the past. I have found that using a cdrw disk made coasters a thing of the past for me and it was a lot cheaper than buying a new cdrw drive.
If the fat lady's singing at least shes losing weight.