The normals should be normally exported. however, you need to flip the normals so that they work correctly. To do this simply (I'm guessing your running 2.49b) press "draw normals" under edit buttons -> Mesh Tools more. Little blue lines should populate the model. now select any face in which the line is pointing the wrong way (it should be pointing out), select it, ctrl f, flip normals. continue on until you are done. Feel free to change NSize to make the normal lines easier to see.
SOBA: FIX YOUR NORMALS! See the bottom of your cup? Fix that! No one wants to see that!