Electronic ballast problem

        I'm just setting up a 30g tank, and I foolishly bought two 20w
(24") tubes and an electronic ballast to power them, even though I don't
know much about fluorescent lighting.  I hooked up the ballast
(Coralife/Energy Savers Double Wizard T-12 kit) and lights (one 20w Triton
and one 20w Beauty Light) according to the box instructions, but the lights
won't light up reliably. Sometimes I can get both lights to come on if I
rub just one of the bulbs with my finger-- as if the electric field in the
bulbs is almost, but not quite, strong enough to get things going. What's
going on? What might I be doing wrong?