My bone's mesh gets exported, why?

Hi again; another issue: My bone structure in max7 is very simple, a belly (root) bone from wich the legs and spine bones goes thru hierarchy; Everythig looks ok, I get correct uv exporting, animation is ok, all, except the spine annoying bone - it's in the second level (right below the root) in hierarchy; with is it being exported with my model mesh in dts? I've tried whith a cylinder animated with 3 bones - again, but in this case the root bone gets exported; I've already tried to not add the root bone to the skin modifier, but nothing seams to happen. Maybe it's a wee bit foo, but for 2 days I'm on it - and I didn't found in documentation or in forums any light to bright my way. What I do to get this fixed? thks!