since you are using slackware (wise choice - i love it as well ), you can either use the tgz from linuxpackages
http://www.linuxpackages.net/search_view.php?by=name&name=virtual&ver=

or add the package from your distro repository via slapt-get/gslapt

the 64bit mod may be the reason for your problems though. i only use slack 32.