I'm very new to modeling and nif-files and I've made a custom armor with different armor parts, both vanilla and from other mods, but when I load it into the game, my body is invisible and broken parts of the armor are floating and appearing randomly around me. In the Geck, the armor-preview showed missing parts, also. During editing in Blender, I sculpted and removed some parts of meshes to fix clipping and recalculated normals for different parts, because some faces faced the wrong way. I use nifskope to put armor pieces together into one nif and edit with Blender 2.49b together with the niftools addon for importing/exporting.
I can upload the nif, if needed.