Since some revision (afaik it comes up near the new Logmanager) you have to explicitely start C::B with the "-d" parameter to start the debug-log.
That's no problem if you start it directly (or via Icon), only when started with double-clicking on a file the debug-log does not open.
I don't know if there is a checkbox somewhere in the settings to open the log always (I did not find), or at least a parameter in "default.conf".
If not it should not be so difficult to create a patch for this.