NEWBIE

Hi, I'm an erstwhile DNS admin and am using BIND 9 on my home network. I
have DNS running and it resolves correctly from both inside and outside
my LAN (I have broadband connection w/static IP). The only exception is
that if if "dig domain.com", I don't get back an answer. Heres' the
reply:
; <<>> DiG 9.2.2 <<>> mydomain
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 54292
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;mydomain.com. IN A

;; Query time: 20 msec
;; SERVER: 129.105.49.1#53(129.105.49.1)
;; WHEN: Tue Nov 9 15:49:07 2004
;; MSG SIZE rcvd: 33


If I query for a particlular service that's configured in DNS, I get
back what I expect. For example query for my web server returns this:

; <<>> DiG 9.2.2 <<>> www.mydomain.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 42851
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.mydomain.com. IN A

;; Query time: 53 msec
;; SERVER: 129.105.49.1#53(129.105.49.1)
;; WHEN: Tue Nov 9 15:53:57 2004
;; MSG SIZE rcvd: 37

It may be that I'm mis-using "dig", but I'm not sure. Can someone help
me out?
TIA