[CentOS] centos 4.4 dns problem -

I've just installed Centos 4.4 on a computer, replacing FC6, and the 
first thing I find is that DNS does not work no matter what I have in 
/etc/resolv.conf.  It should at least work with my ISP's assigned server 
but doesn't.  Numerical URL's work via the browser and ping.  Is there 
something else I need to attend to?

I hope this is the right list for such questions.

Thanks.

Bob Goodwin