I just went through the exact same problem. Before you do anything else try this:
With the bike running, with your fingernail, flick the starter button a few times to see if the light comes on (i.e., partially push the button in with you nail and then let it slid off you nail and SNAP back). Obviously, be careful not to press the button in too far while it's running or the starter will engage the engine. Contacts in the start button assembly apparently (I'm no expert but am quite sure) disconnect the light while engaging the starter so that more current flows to the start circuit. When they get dirty or wear, the circuit sometimes does not re-engage when you release the start button and the light stays off.
I haven't yet fussed with mine enough to know if it can be fixed via electronic cleaner spray or if replacement will be needed but that's where the problem is on mine.
No one on their deathbed ever said "I wish I had spent more time at work".
Last edited by greyhound; 12-05-2008 at 08:24 PM.