What is the shortcut key (Tab?) to activate Zen Coding within Notepad++ once Zen is installed? Could it be F1? Tab is not working. Nothing in Preferences under Editing.
Go to settings > Shortcut Mapper > Plugin Commands tab.
Look for "Expand Abbreviations" it has the shortcut "Alt-Ctrl-Enter" by default. Double-click that line (or hit Modify button) and deselect all checkboxes. Select "Tab" from the drop-down list of available key commands, and boom! Tab now Expands Abbreviations when it finds them, and otherwise functions as the normal Tab.
Hope this helps!