That is exactly the same issue I was having with my board.
http://aussiepinball.com/index.php?topic=14122.0
Pascal believes it's either a diode or transistor on the board that is the problem. You should have got a spare one of each of those with the board.
Check the driver transistor Q1 on the board (just above A3J2). Also check the diode just below Q1.
I still haven't fixed mine. I tried desoldering the diode to start with and simply cannot get it out. I think the fact I have a $15-20 dick smith soldering iron might be part of the problem. 
I don't think it's getting hot enough.
So Im still waiting for a mate to come round with his Hollywood version and will try again then, since I don't want to screw up a nice new board. I might have to finally upgrade to a decent one myself.
Hey thanks Slash, It is what I have been suspecting and you have pointed me in the right direction. I see I have a transistor in the spare bits that came with the board but I would like to get a few spares so does any one know what rating/type they are so I can ask for them at Jaycar?
Dan already knows what I can do to a board so I might take him up on his offer
Thanks heaps for the reply and pointing me to your post.
Cheers: Brettski... :)
