Trouble setting up an RBL list

Hi there,

I manage nameservers for DOMAIN.COM (on tinydns), and have an RBL under 
list.DOMAIN.COM (bind, separate system)

When I do a lookup for Y.Y.Y.Y.list.DOMAIN.COM on a mail server using 
dnscache, I don't get a result.  That is because (as far as I understand 
it, based on tcpdumps on the tinydns box) dnscache asks the tinydns auth 
server for an A or TXT record, which that server doesn't have.

**But if I first do the same lookup for an NS or ANY record, then do the 
A lookup again, it works.  I've tested this with postfis: I'd restart 
dnscache, and tcpdump showed that all rbl queries stop.  As soon as I 
run "host -t ns Y.Y.Y.Y.list.DOMAIN.COM", list queries resume, and I 
start seeing hits in maillog.  The NS record just isn't being offered or 
asked for.

I've gotten around this with "echo X.X.X.X > 
/etc/dnscache/root/servers/list.DOMAIN.COM" on my mail servers   But I 
would want to avoid needing an extra step and have it work just like 
spamhaus or abuseat, where it is delegated automatically.  I'm sure it 
is an issue with my zone, which is below:

.list.DOMAIN.COM:X.X.X.X:list.DOMAIN.COM
Zlist.DOMAIN.COM:list.DOMAIN.COM.:support.DOMAIN.COM:1::::3600
&*.list.DOMAIN.COM::list.DOMAIN.COM

X.X.X.X being the IP of the Bind RBL server.  I know that the last line 
is probably unnecessary, but I was trying different things while 
troubleshooting, and this is the current form.

Can anyone offer some criticisms or fixes?

- Darek