Macro-stdexten - where's the binding?

On a vanilla 1.4.10 install under Ubuntu 7.10 with a simple setup of 2 sip “friends” I would get a message

trying to call from one to another.
The solution was to uncomment macro-stdexten section which is likely mentioned in some place outside the *.conf files.
Now, are there any other non-portions of dialplan (extensions.conf) that should just be there?