I have confirmed the behaviour on Edgy. On Edgy /lib/iptables/libipt_TARPIT.so exists but add an iptables rule with the destination of tarpit errors with "iptables: Unknown error".
However, on Dapper /lib/iptables/libipt_TARPIT.so exists but the error is more informative. "iptables: No chain/target/match by that name"
I have confirmed the behaviour on Edgy. On Edgy /lib/iptables/ libipt_ TARPIT. so exists but add an iptables rule with the destination of tarpit errors with "iptables: Unknown error".
However, on Dapper /lib/iptables/ libipt_ TARPIT. so exists but the error is more informative. "iptables: No chain/target/match by that name"
Subsequently this seems to be a regression.