Anyone familiar with using a Kazzo to dump Famicom carts?

I have been trying to dump some Famicom games with the Kazzo, following the directions outlined here:

http://www.neogaf.com/forum/showthread.php?p=72806661#post72806661

However, when I try to dump a game, I select the mapper, name the file, and just get "Reader open error" when doing Mario 3 (mapper is MMC3). Same thing on a Windows 7 and Windows Vista machine. When I try the game Son Son, I select nrom.ad and get:

AN ERROR HAS OCCURED [the index 'ppu_rom' does not exist]


CALLSTACK
*FUNCTION [dump()] dumpcore.nut line [22]


LOCALS
[ppuarea_memory] NULL
[vram] 1
[increase_ppu] 1
[increase_cpu] 11
[mappernum] 0
[script] "nrom.ad"
[d] USERPOINTER
[this] TABLE

I really have no idea what else to try. I have followed all the instructions, but it does not seem to work!

Thanks for any advice.