some new FreeBSD systems use a newer version of libm.so, so just create a symbolic link back to libm.so.2:
ln -s libm.so.3 /lib/libm.so.2
If you do have this error, then likely the mysql install process also didn't work correctly. Â To reinstall mysql (after making the symbolic link above, type:
cd /usr/local/directadmin/scripts
killall -9 mysqld
killall -9 mysqld_safe
./mysql.sh somerootpass da_admin someadminpass