Setup Bind Dns, Apache, And Vsftpd

I been using plesk, and cpanel so this is the first time I have Webmin for my CentOS.

After some googling and reading, i able to install apache, mysqld and vsftpd (for some reason, my host (hivelocity) didnt install these. So this is my setup.

a.com: in godaddy, i add nameserver host as ns1.a.com and ns2.a.com and change the dns to point to that

b.com: in godday, point dns to ns1.a.com and ns2.a.com
BIND DNS Server

========================

I create two master zone for a.com and b.com
a.com

Code:

$ttl 38400
a.com. IN SOA server.a.com. abc.yahoo.com. (
1226206691
10800
3600
604800
38400 )
a.com. IN A 1.2.3.4
server.a.com. IN A 1.2.3.4
a.com. IN NS server.a.com.
mail.a.com. IN A 1.2.3.4
ftp.a.com. IN CNAME a.com.
www.a.com. IN CNAME a.com.
a.com. IN MX 10 mail.a.com.
b.com
Code:
$ttl 38400
b.com. IN SOA server.a.com. abc.yahoo.com. (
1226206691
10800
3600
604800
38400 )
b.com. IN A 1.2.3.4
server.a.com. IN A 1.2.3.4
b.com. IN NS server.a.com.
mail.b.com. IN A 1.2.3.4
ftp.b.com. IN CNAME b.com.
www.b.com. IN CNAME b.com.
b.com. IN MX 10 mail.b.com.

APACHE

========================

I created 2 virtual servers for a.com and b.com
/home/sites/a.com/html
/home/sites/b.com/html

I create an index.php in a.com/html with content: "a.com YEAH"

I create an index.php in b.com/html with content: "b.com YEAH"

After wait for dns to propogated,

when i try to go to a.com, content "a.com YEAH" shows up.

But when goto b.com, content "a.com YEAH" shows up? Why?

Also, when goto ns1.a.com, content "a.com YEAH" is there.

I also has problem with vsftpd but let fix that later.