Also as possible workaround you can enable IPv6 on network interface without assigning real IPv6 address.
# nano -cw /etc/sysconfig/network
NETWORKING_IPV6=yes
#nano -cw /etc/sysconfig/network-scripts/ifcfg-eth0
IPV6INIT=yes
IPV6_AUTOCONF=yes
# nano -cw /etc/modprobe.conf
alias ipv6 on
# service network restart
How can I enable IPv6 under Debian Lenny?