Some lookups work, wome don;t

[GK]

Quick question.  New to this DNS stuff.  I have a DNS server running.  I

can get to my web site www.calgarywebsite.com from some ISP's but not
others.  For example, from work, I can get to the website no problem.
The name is resolved.  But if I try from one of my dialup accounts, it
can't seem to resolve the name?  Why would that be.

Other people have told me they can't get to the website as well.  While
others say they can.

What causes a client to goto the secondary DNS server?  Currently my
secondary dns server is dead.  Is that the cause?  There is no traffic
at this website.  I would assume that they would all hit the primary DNS

server.  I think I must have something configured wrong.

Thanks