Summary
The remote host is missing an update as announced
via advisory SSA:2007-314-02.
Solution
https://secure1.securityspace.com/smysecure/catid.html?in=SSA:2007-314-02
Insight
The security/bug fix update for Slackware 11.0 has been reissued to fix a zero-length /usr/bin/php-cgi. Thanks to TJ Munro for pointing this out.
Sorry for any inconvenience.