this is due to a bug in mysqlinstallation I think. Try adding the the directory where this file exists to your /etc/ld.so.conf file and run
ldconfig
so your system knows where to find the library.
If apache starts crashing silently (it did with me) you might have mysql installed from rpm, which contains a bug from compiling with glibc --with-posix-threads enabled. A installation of mysql from source by default disables this and should work.
good luck
nicholas