thunderbird 64 bit version

If one executes the thunderbird 32bit on 64bit machine, one could see the following error message:

(thunderbird:19701): Gtk-WARNING **: /usr/lib/gtk-2.0/2.10.0/engines/libclearlooks.so: wrong ELF class: ELFCLASS64

So I download the 64bit version thunderbird via http://releases.mozilla.org/pub/mozilla.org/thunderbird/releases/latest/linux-x86_64/en-US/

No error messages are displayed when I execute it.