Why does BURN-Proof make a gap? This is what Sanyo tries to explain to us:

"...BURN-Proof predicts generating of a Buffer Under Run error, and when it is judged that it becomes an error, the drive once interrupts record. After receiving the record data, the drive searches the recorded area and compares the data on the disc with the data in the buffer memory so that it can restart seamless record at the discontinuation point of record..."

Check the whole article over here