All drives lost in extended DOS partition?



Recently I lost all logical drives in extended DOS partition when PC spontaneously restarted while creating DVD image file using Nero Image Recorder. A few months ago I had exact same result when I opened DVD burner while running DVDShrink on some files created by DVDDecrypter on the hard drive, i.e. that also resulted in spontaneous reboot and loss of all logical drives in the extended DOS partition. These 2 separate instances occurred on 2 separate systems with different DVD burners with both systems running Windows 2000 SP4 and latest updates and 512 MB of memory. Has anybody experienced such odd behavior related to DVD burning activity? I might avoid possible recurrence of the first instance simply by not opening the drive while any DVD process is running, but I have no clue what caused the latest incident in which reboot seemed to have no explanation.