Sound on Linux sucks. This has been an issue since the beginning, and it has gotten a lot better, but it still really sucks. Any given application is likely to support only a subset of the numerous sound systems (OSS, Esound, aRts, ALSA, PulseAudio) and if it doesn’t support the one you use you’re likely to run into at least some trouble. Sometimes there are wrappers available (intended to make it possible for a technically-inclined user to get problematic applications working) but they’re not 100%.
The root of this complaint in my case is Skype. Yes, it’s an evil proprietary baby-seal-clubbing binary, but it’s what my friends use to communicate and it’s the #1 VoIP app. In order to get Skype to work properly, I have to quit all other applications that are playing sound, even if they’re not currently doing it. I can’t leave Rhythmbox paused – I have to quit. If I’ve watched a single YouTube video with sound, I have to quit Firefox (this is really obnoxious if it means I’ll have to log in to a site again after Skyping). If any music application is still open, Skype just gives me a lot of:
ALSA lib ../../../src/pcm/pcm_dmix.c:874:(snd_pcm_dmix_open) unable to open slave
I’ve tried using the padsp wrapper with the statically-linked OSS skype binary (honestly, should anyone really have to know any of those terms just to chat online???) but the sound quality is basically unusable due to static noise. I can understand the desire of developers to rectify mistakes in previous sound subsystems, but not providing seamless backwards-compatibility paths for at least ALSA and OSS seems inexcusable to me. Note that I would be in the same situation if I had an old open-source application that was just unmaintained and too complex for a hobbyist developer to fix – this problem is not inherently caused by Skype’s closed-source nature.
I can’t even remember having issues like this in Windows in the past 10 years.
Update: After a few months, I eventually got Skype working!