When you got K49, did you also get kernel-modules? I ask because sometimes multi-function devices like this show up literally as a dual device, one for audio and one as an "aux keyboard" or such. Try this: On stock kernel, do an lsmod when BH-214 is not connected. Then connect it and do another, diff the two outputs. It should be loading at least one, maybe up to 3, kernel modules. Minimally, if the modules are already loaded, it should show a link-count increase from the device activly linking into it. Then repeat this on K49. It could be as simple as a missing module, or something not loading correctly.