SMB3 is a game that should get imported, it is super popular, has tons of Meta Data behind it so I wonder if LB is having issues... Have you imported games with "force importing duplicates" to see what happens?
Also, this isn't a solution for all 130ish games that didn't get imported, but have you tried adding 1 game by its self?
Take SMB3, in the bottom right there is an add button. Press it, input the games name in the top, select the platform it belongs to in the drop down (so Nintendo Entertainment System (NES)). The first browse box on the bottom hit browse and select the rom from that menu. Then back in the edit box hit the emulation tab, select the check box and choose the emulator you use from the drop down menu. It is a bit labored vs the rom importer but see if that works.