I tried it many times and it always happens again. Burning a rewritable CD in my i-book (600 mhz, 256 ram) under System 10.1.4 (same in 10.1.2, 10.1.3) is not possible. Neither using Apple's burning software nor using Tost 5.1.3 works. The burning process stops always immediately and an error message appears that says "the drive reported an error sense key=illegal request sense code=0x27 write protected" The same Cd can be burned trouble free on other computers under the same system software. Is that a hardware or a software problem? Single session CD-R burning is trouble free. (internal Sony DVD/CD-RW) Help is very much appreciated.