Steven Erat has a great blog post regarding ColdFusion caching hostname resolution. Essentially there are times when tags within ColdFusion look up domain names and map them to an IP address. The ColdFusion server then remembers that information. This is all a good thing.
However people sometimes get into trouble when they have a development and live web site on the server, and switch IP's of the two addresses (such as changing the dev site to the new live site). The old site information is still remembered by ColdFusion potentially causing errors, corrupt data or worse.
This can cause problems for Savvy CM users if they have just set up a new domain for Savvy, or recently changed it. If you find you can no longer create new pages with Savvy, have the ColdFusion service restarted. A quick way to test this is to have a web browser opened on the server hosting your web site. If it doesn't' resolve the web sites correctly you have a problem.
Visit Steven's blog for more detailed and technical description and how to change the configuration on the server if you need to.