Why the latest build of DirectX?

Sorry if this question exists somewhere, but I searched already and found nothing.

Is there a reason the developers use the very latest build of DirectX? I'm thinking of casual games, where a few of the more recent games require DX9 but don't require the end user to install the very latest build, which for the casual market could potentially lose sales.

I absolutely love Construct and the way it's heading, but this is the only thing that's deterring me from using it to make a casual game.

Thanks.

Probably because XAudio2 is involved and Direct Sound is going to be obsolete.

XAudio2 was only recently released in a DirectX update, so we kind of have to guarantee everyone has the latest DirectX so sound can work. Also, newer DirectX updates have newer D3DX builds which have bug fixes. Still, the more time that passes by, the less of a problem it'll become. I might be able to figure out a way to compile the runtime with the DirectX update built in so it wouldn't be a problem.

Ah thanks for the replies guys. I thought it might be to do with bug fixes but wasn't sure. Good to know you're working on that Ashley along with the other 999,999 things. I'm sure many of us would appreciate that!

XAudio2 was only recently released in a DirectX update, so we kind of have to guarantee everyone has the latest DirectX so sound can work. Also, newer DirectX updates have newer D3DX builds which have bug fixes. Still, the more time that passes by, the less of a problem it'll become. I might be able to figure out a way to compile the runtime with the DirectX update built in so it wouldn't be a problem.

an option to do that would be greatly appreciated!