you may want to post coding questions on either the 3rd party or haiku-dev mailinglist. Coders usually only stumble by accident upon forum posts.
The #haiku IRC channel is also a promising option.
However checking it out, I suspect that this is not even a coding problem, as I get the same error message from Jabber4Haiku if I start from command line and enable sound effect. It is more a problem with my sound setup on my Haiku box.
i have the same problem. It seems compiling with gcc2 works, but when i compile with gcc4 i get the same error. I filled a bug report, and hopefully this bug is solved soon. http://dev.haiku-os.org/ticket/7625
Too bad you didnt write a bug report when you met that problem.
I have the same problem. I am pretty sure the problem was introduced when Stippi rewrote the media server. My code ran until the update. My bug is logged here: https://dev.haiku-os.org/ticket/7587