bind9 chaotic freeze problem?

[Mike]

Fedora Core 5
kernel-smp-2.6.18-1.2239.fc5
bind-utils-9.3.3-0.2.rc2.fc5
bind-libs-9.3.3-0.2.rc2.fc5
bind-chroot-9.3.3-0.2.rc2.fc5

At some chaotic interval my box will hang to the extent
that I cannot even 'ls -l /tmp' (may not pertain to anything).
I cannot 'shutdown -fr now' the box until I kill named. Once
I restart the box things are ok until the next time this happens.
I am running 'top' and do not see named spinning. I am going to
cause named to do more logging (named -d 3?) to see what's going
on. Any suggestions to what might be causing the problems?

Mike