You do actually have a rather rare cart there. In fact I just emailed like 30 ebay resellers a couple days ago, many of which had many copies of the game. And only 2 had this one and so now I finally have one on the way. What you have there is "Revision 0", which must have some bugs or something, because the vast majority are revision A.

I've been running a redumping project for the NES, that is one of the last few revision 0's that hasn't been dumped. I have a site setup http://bootgod.dyndns.org:7777/

that covers everything that has been done so far.