Two domains + one IP + ignorance = request for assistance

I'm stuggling with a problem undoubtedly due to ignorance… I've been searching for hours for a ready-fit explanation on the web with no luck. So let's try asking for help…

I've got two domain names, www.pointergames.com and www.splodey.com… both referring the the same IP and content. These were hosted by GoDaddy until yesterday, when I made the switch to Linode. One works (pointergames) and the other doesn't (splodey). I'm using name-based virtual hosting, with which I do have experience on the LAMP server in my home.

I believe I must be doing something wrong with the DNS setup… the use of A and CNAME records is new to me.

A "whois" shows that Linode is the name server for both domains.

So the question… using the Linode DNS, how does one route two domain names to one IP?

Thanks,

Mark