That problem with no sound,when installing the new libc6,still existing or already is resolved
4bff6e0175ed195871f4e01cc4c4c33274b8f6e3 is the first bad commit commit 4bff6e0175ed195871f4e01cc4c4c33274b8f6e3 Author: Andreas Schwab <schwab@redhat.com> Date: Fri Feb 25 20:49:48 2011 -0500 - Fix memory leak in dlopen with RTLD_NOLOAD (BZ#12509)