Ah but you forget two things: one is that it DID work with calibre one time. However even after i went back and reconverted the same file with the same settings, it stopped showing up. The second is i also copied the Guttenberg mobi project without using Calibre at all and it wouldn't site up. This is why i think the problem is on the kindle side
It sounds like this Kindle Previewer does similar things to Calibre, will it let me format Guttenberg project mobis to be compatible with kindle fire with little work on my part? I don't know what toc.ncx is and don't think it sounds like i want to learn proper toc.tcx if it's something i have to do by hand.