We challenge you to find a major new tech product launch that isn't accompanied by a handful of issues in the field. It's hard to do — and the Galaxy Nexus is no exception, it seems, with reports coming out of the UK that the device's volume is occasionally going to zero uncommanded (a condition sometimes referred to as "mute"). Furthermore, it seems to stick there for several seconds while the device becomes unresponsive, so you can't immediately fix it... but that's assuming you notice it. If you don't, the danger of missing notifications gets a lot higher.
Users seem to be noticing that 2G service is somehow related — the problem is being reported with greater frequency when the Galaxy Nexus is either connected to or in the process of switching to 2G. We checked in with a brick-and-mortar O2 store today which told us that there haven't been any complaints or returns related to the issue (their units are running build APA28, for what it's worth). If there's a bright side to this, it's that this sounds like a software problem, not a hardware one — so we're cautiously optimistic that this'll be fixed with a standard-issue OTA update.