'www' CNAME is not resolving properly, root A records working fine though (for Heroku)

I'm having trouble using WHM/Cpanel to set up CNAME records for my heroku app.

I've set up the records as follows - see link to image.

dapcards.com is resolving to the heroku app with no problems.

However, www.dapcards.com fails:

> host dapcards.com
dapcards.com has address 75.101.145.87
dapcards.com has address 75.101.163.44
dapcards.com has address 174.129.212.2
dapcards.com mail is handled by 0 dapcards.com.
> host www.dapcards.com
Host www.dapcards.com not found: 3(NXDOMAIN)
Host www.dapcards.com not found: 3(NXDOMAIN)

When I use the dnsstuff.com tool, it seems to get to proxy.heroku.com fine, but produces an error:

[BOGUS ANSWER: This server is not authoritative for proxy.heroku.com.: 
it refers back to the root servers]

http://www.dnsstuff.com/tools/legacy/?formaction=DNSL开发者_运维百科OOKUP&ToolFormName=customlookup&name=www.dapcards.com&r=235660&detail=0&type=CNAME

I'm obviously missing something here. Has anyone got any ideas? Would really appreciate some advice!

Cheers, Rob

Perhaps you didn't wait long enough for DNS to propagate? Looks fine here:

$ host www.dapcards.com
www.dapcards.com is an alias for proxy.heroku.com.
proxy.heroku.com has address 50.16.233.102
proxy.heroku.com has address 174.129.212.2
proxy.heroku.com has address 75.101.145.87
$ host dapcards.com
dapcards.com has address 75.101.145.87
dapcards.com has address 75.101.163.44
dapcards.com has address 174.129.212.2
dapcards.com mail is handled by 0 dapcards.com.

I just accessed your website unter both www.dapcards.com and dapcards.com in my browser and the site renders fine :)