Hint : flashplayer9 depends on linux libssl.so.5, and fc10 userland brings libssl.so.7. I wrote that Flash goes perfectly but i haven't checked sound. Indeed, there was no sound, and after checking flasplayer9's library links, it missed libssl.so.5. Just created symlink libssl.so.5 that points to libssl.so.7 (both inside /usr/compat/linux/lib), and everything works fine.