the test I did was , I loaded a hmp with textures applied (which is what I presume you do) then I replaced the skins with different textures , I then saved it ,removed the entity , and loaded it ,everything were correctly saved and applied ..

I also tested with ent_reload but this one seems to have a problem , because it doesn't reload the whole mesh , possible a bug there with terrain and ent_reload?

are you saving your modified files before saving the hmp ? or are you altering the skins bmp's then saving just the hmp ?

I wil conduct some bmp_lock ,with alterations on the pixels tests today .