Some Videos, I was watching in flashplayer under Linux behaved a little weird and had distorted sound with some beeping. Basically the sound was understandable but heavily distorted. An Internet search revealed that it has todo with some obsoleted use of memcpy in flashplayer.
I found the solution in this thread:
Basically, it's enough to start iceweasel (or your favorite browser) as t=following:
or you can create /etc/ld.so.preload with /usr/lib/x86_64-linux-gnu/libc/memcpy-preload.so as content.
Hope this helps one of you.