TEH,

I'm used to sailing 2-up and I also have issues holding the boat down 1-up. Partly this is because my mast and spreader settings are for 2-up configuration.
What I have also learned already is that you can point quite a lot higher then with the jib up (and if you point higher you have less lift ofcourse). I only point well 1-up if I have an A-cat to compare my heading with, otherwise I'm way too low... :-)

Gill