The Karnov ROM is commonly found with the wrong header on it. It should be mapper 206, not mapper 4. This IPS will fix it:

http://rainwarrior.ca/projects/nes/karnov_header_fix_206.ips

This should correct garbage graphics on the second screen of the game, on some emulators and Everdrive N8.

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If you've got a PowerPak, though, you'll get an unsupported mapper error, so if you need to reverse this correction:

http://rainwarrior.ca/projects/nes/karnov_header_unfix_4.ips