I think Directsound works if you have a Creative card and special drivers. I'm not convinced Directsound is a viable audio engine for games any more, because it simply will not work for a significant number of users. You can carry on making games with it - but you might get a lot of your Vista users telling you they hear nothing. Because of this, I don't want Directsound to come with Construct any more, so it's deprecated and I plan on entirely removing it by 1.0.
I'm hoping to completely reproduce Directsound's featureset in XAudio2 so it should be entirely possible to move your game over to the new plugin. XAudio2 also has many improvements on Directsound - I've finished adding OGG support now, which means it can play PCM, ADPCM, xWMA and OGG files on channels - whereas Directsound is stuck with just PCM. It's also got volume metering and other benefits. I really don't think Directsound should be kept as a plugin so I do insist that it is removed ASAP.