"cdrecord -prcap" failed

Since Linux kernel 2.6.8 CDWserver (the server of webCDwriter) has to run with "root" privileges to enable cdrecord to burn CDs. Adjust the file /etc/CDWserver/config-root as follows:
#
# After changing this file restart CDWserver by
#       /etc/init.d/CDWserver restart
#

user=root
group=cdwserve
and restart CDWserver by
$ su
$ unset SUDO_COMMAND
$ /etc/init.d/CDWserver restart