sjurick, it worked! i guess it had something to do with the nonmanifold geometry, but i'm not sure. when you create polygon text in maya, it creates a flat text. extruding creates 3d text. when i deleted the faces on top and on the bottom of the 3d text, boolean difference was not a problem anymore. i am not sure if extruded text is nonmanifold geometry, but it certainly pointed me in the right direction. thanks!

tiz