EZF Advance III on the DS Lite?

I've tried searching high and low for the answer, so perhaps one of you could help me with my plight.

I have an old EZF Advance III flash cart I used to use on my GBA. Now, all I currently own is a DS Lite and I would like to play some of my old GBA backups on it (especially since my GBA games seem to be lost in my closet somewhere -_-)). But yeah, the cart doesn't seem to function in the Lite... probably due to a firmware update to the system, which I have read about how using a passkey could override.... but....

I don't have a passkey, nor do I want to purchase anything to be able to play my GBA backup cart in my DS Lite. The cart worked in my old regular DS when I had it, but this one isn't even recognized. Is there a way around all this?

well that's funny as i have a EZF advance II flash cart and that works fine with the DS lite and gba player, maybe it doesn't work because you have a flashed DSlite?