Maxim, as you told me "Default Editor Tab" selection means default editor tab selection for new created jsp file (for example), in other rest cases vpe remember it's last open state. When i press "Preferences" and "Default Editor Tab" i expect to change something usefull for current editor.
We can easy remove it and always open "Visual/Source" for new created files.
Or it should be renamed into something like this "Default Editor Tab for new VPE files" - this name help you avoid questions.