Please try selecting individual layers and applying optimal transperencies on each one of them, and not on the entire group at once. Please let me know if it worked for you.
If the logo was composed of different layers in AI, maybe you flattened them (by choosing to remove layers) when importing the AI file in to Flash. However, you can retain these layers when importing and using the AI file in Flash. Do you remembering flattening your AI file when importing it in to Flash, i.e remove all AI layers and import the file? If so, try importing again without flattening the file. Then, the layers will be retained within Flash, and hopefully you can add transperency to individual layers.
Please let me know if that clarifies, else I am happy to give you more information and explanation.
Europe, Middle East and Africa