Well... I don't have 3DS, (well, not installed at least)
and I've done just fine so far....
When you use Anim8or , did you do exactly what the tute said to do?
you need to go to object/import on the menu bar, import your object.
and then go to options/debug and make sure the Dummy 3DS Kdata is checked off..... then export it as 3DS format and you should be ok when importing into O2