Retrace done:
...
#4 0xb7e06460 in pthread_mutex_lock () from /lib/tls/i686/cmov/libpthread.so.0
#5 0xafb92858 in ?? () from /usr/lib/flashplugin-nonfree/libflashplayer.so
#6 0xadd52024 in ?? ()
#7 0x09347998 in ?? ()
#8 0xb77d6136 in munmap () from /lib/tls/i686/cmov/libc.so.6
#9 0xb004412c in ?? () from /usr/lib/flashplugin-nonfree/libflashplayer.so
#10 0x00000000 in ?? ()
--- end of stack trace ---
...
Retrace done: i686/cmov/ libpthread. so.0 flashplugin- nonfree/ libflashplayer. so i686/cmov/ libc.so. 6 flashplugin- nonfree/ libflashplayer. so
...
#4 0xb7e06460 in pthread_mutex_lock () from /lib/tls/
#5 0xafb92858 in ?? () from /usr/lib/
#6 0xadd52024 in ?? ()
#7 0x09347998 in ?? ()
#8 0xb77d6136 in munmap () from /lib/tls/
#9 0xb004412c in ?? () from /usr/lib/
#10 0x00000000 in ?? ()
--- end of stack trace ---
...
Tagging as mt-confirm for further processing
Looks a flashplugin-nonfree issue