Nice game. <img src="smileys/smiley1.gif" border="0" align="middle" />
As harrio said, you can simply fly high enough to spawn the points and UFOs, then drop back to the ground and pick them up endlessly. Would it be possible to have the event which spawns the points also destroy the ground? If you did that, and falling down off the screen had the same effect as zealously flying out the top, you'd fix the scoreboard breaking issue with the game as-is.
Keep it up. <img src="smileys/smiley20.gif" border="0" align="middle" />