BIND9.1.1rc3 not compatible with rc2

[Systems]

Currently running fairly smoothly using BIND 9.1.1rc2, able
to perform normal zone transfer and mostly normal stuff.

But, testing with the new rc3 show that server running rc3
cannot do zone transfer with the existing named.conf configured
for rc2.

Check the compilation, and nothing dramatically different from
that of rc2. All servers are the same UNIX version. No different
makes of machines and OS. rc3 just refuse to work together 
with rc2.

Thanks!