can you please provide a test file with packed sounds? because it works perfectly here...

ah and in case you're using 2.59 or older (so no latest development build), make sure the sound file is mono and not stereo, otherwise it doesn't work as well (this changed in trunk/2.6)

It works with recent svn version (40156). At least with a mesh. It is not working with a speaker object. But i don't know if this is the intentional behavior, as i'm not really into BGE.

Steps:
1. add a keyboard sensor to the default cube (assign a key to it).
2. connect the sensor to an "AND" controller.
3. connect the "AND" controller to a sound actuator.
4. open a sound in the sound actuator and enable 3D sound.
5. start game engine and press the assigned button.
6. the sound plays fine.

Do the same with a speaker object. Plays nothing. But i guess this is intentional?

Yes, the BGE ignores speakers. Closing.