Hi, I've just started using V-Vocal as a learning tool to teach me to sing on pitch but I notice that V-Vocal always identifies my vocals at exactly one octave below what I'm singing at. For example, singing a simple scale from G4 to D5 and V-Vocal will show it as G3 to D4. I have a high voice with little sub-harmonics so, basically, V-Vocal has got it wrong. Is there a way to tell V-Vocal to offset it by an octave?

Where are you getting your MIDI note numbers? Some keyboards start numbering from C0 and some start at C1. 

See this article: 
http://www.electronics.dit.ie/staff/tscarff/Music_technology/midi/midi_note_numbers_for_octaves.htm