The remote host is missing an update as announced via advisory SSA:2005-203-02.

https://secure1.securityspace.com/smysecure/catid.html?in=SSA:2005-203-02

New kdenetwork packages are available for Slackware 10.0, 10.1, and -current to fix security issues. Overflows in libgadu (used by kopete) that can cause a denial of service or arbitrary code execution. More details about this vulnerability may be found here: http://www.kde.org/info/security/advisory-20050721-1.txt