CompuServe Messages

I am trying to map images created in photo-shop on transparent surfaces, in photo-shop I created an image using several layers, then copied each layer to new individual .PSD images with transparent backgrounds and saved each out as a 32 bit targa, I then went into the Materials Editor and applied each image to a material with the Targa as a texture map and as an opacity map with alpha selcted, it work closely to what I wanted but there was a drop shadow, and several thin lines that didn't appear in the rendering, has anyone encountered a similar situation, are there any sugesstions? Joe Giannasio