bind9: '-u not supported on Linux kernels older than 2.3.99-pre3 when using threads'

[Andre Dietisheim]

bind9 seems not to support the '-u' parameter ('-u not supported on Linux
kernels older than 2.3.99-pre3 when using threads') on Kernel 2.2.
Does anybody know the reason for that decision?
I already read that bind9 drops userrights quite early, so that you have to
make the config-files world-readable.
I wonder if it is reasonnable (viewed from a security-focused point of
decision) to start named as root or if it is better to change ownership of
the executable & make the config-files world-readable.

Thanks in advance