Must I have "." zone?

[Christine.Tran at East.Sun.COM]

Experts,
(BIND 8.2p1)

jelly.com and pb.com wants to share internal DNS info behind their firewall.  
ns.jelly.com uses forwarders 1.2.3.4 for Internet stuff and 5.6.7.8 for pb.com.
I don't have hint file because ns.jelly.com can't connect directly to Internet.

        options { ...blah... forwarders { 1.2.3.4.; }; };
        zone "pb.com" IN { type forward; forwarders { 5.6.7.8; }; }; 
        zone "jelly.com" IN { type master; file "jelly"; };

I turn on debug level 1 and when I querry for internet8.pb.com. I can't find it:
        No root nameservers for class IN
        prime_cache: priming = 0

I throw in the "." zone and the hint file and it works, even though 
ns.jelly.com can't connect to any of these root name servers, though not for
lack of trying.

        Q1) Must I have a "." zone and a hint file even when I don't use it?
           If yes, can I put any fool thing in the hint file?

        Q2) I am reading DNS&BInd 3rd.Ed p 387 about Internal Roots and I
        don't have a large name space, nor lots of internal name servers, nor
        are they geographically distributed.  I don't want to create internal
        roots.  Why won't my forward pb.com statement work without them?

QCT