I thought setting up an IPC Zone fixed this sort of problem. However reading the WDM Driver Wiki, maybe not.
Worth a try though.
Hi
I'm going to assume that you have set up a specific zone for the driver, as Roderick indicated. Also that you have set up a zone switch rule. (Off Topic - People that don't have a separate zone, and I think there are a lot of them, are using "WDM" latency settings which in IMHO are probably not good to use for local playback. They complain of pops and things because there latency is set too low etc.)
Now I also have some problems like you are describing, but I use a simple work around which is not too much of a pain for me.
I set up azone for WDM playback only (IPC) - define your zone switch rule like in the wiki
The I choose a zone for local playback and again define the rule.
If I set each zoneswitch rule to stop playback in both zones (as described in the wiki btw), I have to manually stop "playing now" or suffer what the Octavist is describing.
So what I do is make the first rule the WDM zone and edit the rule to stop playback in the other zones, making sure the local playback zone is the
second rule as the order is important. And then leave the stop playback box empty.
This sound counterintuitive maybe, but the idea is that normally my "default" zone(s) is my local playback zone which is loaded on launch. Sometimes I go on the internet to stream something or watch a video. The zone switch kicks in, stops the local zone(s) and plays fine. If I want t go back I stop playback manually, before using my default zone again. The zones are still automatically changed, just only one zone can stop the playback of the other. Sure its not ideal especially if you are constantly going back and forth form local playback to streaming.
Now for the OP, he might want to try the other way around with the playback zone as the first rule that stops the WDM zone instead of the way I do it. Sort of depends on what tends to be your default. And which zone is more important to automatically switch AND stop playback.
I'm sort of hoping that the reason zone switch is now under audio options, per zone, that they plan to address this issue. It seems that at present the zone switch rules are still global, right??
In the mean time at least I can use the WDM driver for streaming which is worth the work-around. As I have a remote connected its pretty easy for me to hit the stop button.