I do not want to try:
$ ln -s /lib64/ld-linux-x86-64.so.2 /lib/ld-linux-x86-64.so.2
Because I have both files and not sure what will happen then. it is ok?
I use Fedora 14.
there won't happen anything bad if you do that.
Fedora (or RHEL in general) keeps ld-linux-x86-64.so.2 only in /lib64 while many system also have that symlink in /lib.
(note that you don't have that file in /lib, yet, there's only ld-linux-x86.so.2 (note the missing -64))