Valid Serial and Expire?

[M & J]

 1999110201 ; serial
                        8 ; refresh
                        2 ; retry
                        1 ; expire
                        1 ; default_ttl

Is this a valid set of records?  I updated the serial to today.  The problem
I am experiencing this that the world can no longer see to my name server.
When I do an nslookup on my server (localhost) all is ok, but when I try
nslookup on another name server, it fails.  I figured refreshing the serial
# may help.  Am I way off here?

Any help appreciated.
My understanding on this is a bit weak.

Mark
mhutch at cadvision.com