I have translated the language file for profile book... it is available in this post for download... Don't forget to change the file name to just: spanish.php before uploading to server.
most likely you already figured it out, but as ive just have the same problem it doesnt hurt me to take a couple of minutes and write it down.
you have to upload it here:
/components/com_comprofiler/plugin/user/plug_cbprofilebook/language/