The problem appears to afflict a select group of devices that properly handled Xbox 360 audio prior to the New Xbox Experience, such as the BenQ G2400W monitor. It is believed that the issue stems from an updated HDCP handshake--the protocol used to establish an HDMI connection--which the older devices are not compatible with.
Now, Microsoft has acknowledged the issue in a statement to Shacknews, apologizing for the "inconvenience" and noting that a fix is in the works. Said Microsoft:
While the vast majority of our users worldwide are enjoying the New Xbox Experience with no problems, we are aware that a handful of Xbox LIVE users are experiencing audio issues, and are diligently monitoring this issue and working towards a solution. We appreciate our members' enthusiasm and patience, and apologize for any inconveniences.
A temporary fix was also discovered--remove the hard drive, boot the system, then insert the hard drive after the dashboard comes up--but the workaround does not function for everyone, and must be performed each time the system is turned on.
Thanks to Shacker Vergs for the heads up.
Interesting that this wasn't picked up in the Beta even, must be an incredibly small number of users affected.
It's not. There are 2-3 threads,11 pages long, with people with the same problem involving all sorts of different monitors. What was irritating is that it garnished no response from Microsoft and the customer support via telephone was clueless about it.
Keep in mind that small is unfortunately relative.
If 10,000 users were impacted, MS would statistically need to test this on something like 2,500 systems before a single one reproed.
Now, chances are it isn't random. Hopefully they can figure out what is common about these systems and add it to their test matrix. Its likely there is some hardware version or some previous software state (ie what update people were on, etc) that cause the issue. Once this is tracked down, that source of problem shouldn't happen again.
On the lack of response... until a significant number of complaints are lodged, the problem is indistinuishable from noise (ie 100 people had problems shortly after installing? That could just be regular 360 failures that happened to occur after the patch - or it could be a new issue). Generally, customer support doesn't find out about this stuff until after a bunch of forum posts.