Softimage Xsi: HELP!!! hair with FG

Well, i did some white hair to my character, rendered it and it was ok. Then i imported him to a scene with hdr picture mapped on sphere and FG and i discovered that when i render, all the white hair turns black! I tried some presets of hair from the library and to change the ambience but with no sucsess. WHAT IS THE PROBLEMMMMM!!! Help me if you can! Please!

huy again! i tried to remove the hdr and left only FG and it is not helping! what is the problem? is it happens only to me?