My CD-R discs all corrupted by freebsd.

[Aminavy]

Try setting the write speed to 24X, or something else lower than the maximum. Use the configuration file in /usr/local/etc/ so this doesn't have to be set on the command line each time.

When I lowered the speed from the maximum, cd's burned correctly.

You mean your cd's incorrectly burns with more speeds?

I'm not played with speed yet.