with my old Kernel 2.4.20 i could activate masquerading with

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

now i built a 2.6.5 kernel with nearly all iptables options as modules, but this command now gives me this error:

Code:
iptables: Invalid argument
Portforwarding doesnt work anymore too, but all other iptables commands work. I used the same kernel setup on another computer too and it worked there, the only differences between these 2 kernels are the hardware driver options.

I allready loaded all the modules i found that have to do something with iptables, and enabled forwarding over the proc filesystem.

Does anyone know what I'm doing wrong?

Code:
root@troll kai # cat /proc/sys/net/ipv4/conf/all/forwarding
1
root@troll kai # cat /proc/modules
ipt_TCPMSS 4032 0 - Live 0xe123f000
ipt_tcpmss 2240 0 - Live 0xe123d000
ipt_recent 10636 0 - Live 0xe1242000
ipt_multiport 2112 0 - Live 0xe123b000
ipt_pkttype 1792 0 - Live 0xe1239000
ipt_owner 3968 0 - Live 0xe1237000
ipt_NETMAP 2176 0 - Live 0xe1235000
ipt_mark 1792 0 - Live 0xe1233000
ipt_mac 2048 0 - Live 0xe1231000
ipt_length 1792 0 - Live 0xe11fa000
ipt_iprange 1920 0 - Live 0xe11f8000
ipt_helper 2304 0 - Live 0xe11f6000
ipt_esp 1984 0 - Live 0xe11f4000
ipt_ECN 3008 0 - Live 0xe11f2000
ipt_ecn 2176 0 - Live 0xe11f0000
ipt_DSCP 2432 0 - Live 0xe11ee000
ipt_dscp 1792 0 - Live 0xe11ec000
ipt_CLASSIFY 2176 0 - Live 0xe11e5000
ipt_ah 1920 0 - Live 0xe11e3000
ip_queue 9432 0 - Live 0xe11e8000
ip_nat_tftp 3184 0 - Live 0xe1212000
ip_nat_irc 3952 0 - Live 0xe1210000
ip_nat_ftp 4656 0 - Live 0xe11c1000
ip_nat_amanda 2556 0 - Live 0xe11bf000
ip_conntrack_tftp 3312 0 - Live 0xe11bd000
ip_conntrack_irc 70832 1 ip_nat_irc, Live 0xe11fd000
ip_conntrack_ftp 71600 1 ip_nat_ftp, Live 0xe11aa000
ip_conntrack_amanda 68960 1 ip_nat_amanda, Live 0xe1198000
ipt_ULOG 6216 0 - Live 0xe1195000
ipt_ttl 1984 0 - Live 0xe1193000
ipt_tos 1728 0 - Live 0xe1191000
ipt_SAME 2432 0 - Live 0xe118f000
ipt_REDIRECT 2176 0 - Live 0xe118d000
ipt_MARK 2112 0 - Live 0xe10b9000
ipt_REJECT 5824 7 - Live 0xe10dc000
ipt_LOG 5632 17 - Live 0xe10bc000
ipt_state 1920 2 - Live 0xe10d7000
iptable_filter 2624 1 - Live 0xe10ab000
ipt_MASQUERADE 3456 0 - Live 0xe109e000
iptable_nat 22244 9 ipt_NETMAP,ip_nat_tftp,ip_nat_irc,ip_nat_ftp,ip_nat_amanda,ipt_SAME,ipt_REDIRECT,ipt_MASQUERADE, Live 0xe10bf000
ip_conntrack 29996 15 ipt_NETMAP,ipt_helper,ip_nat_tftp,ip_nat_irc,ip_nat_ftp,ip_nat_amanda,ip_conntrack_tftp,ip_conntrack_irc,ip_conntrack_ftp,ip_conntrack_amanda,ipt_SAME,ipt_REDIRECT,ipt_state,ipt_MASQUERADE,iptable_nat, Live 0xe10ad000
ipt_TOS 2368 101 - Live 0xe10a0000
iptable_mangle 2560 1 - Live 0xe109c000
ip_tables 17152 33 ipt_TCPMSS,ipt_tcpmss,ipt_recent,ipt_multiport,ipt_pkttype,ipt_owner,ipt_NETMAP,ipt_mark,ipt_mac,ipt_length,ipt_iprange,ipt_helper,ipt_esp,ipt_ECN,ipt_ecn,ipt_DSCP,ipt_dscp,ipt_CLASSIFY,ipt_ah,ipt_ULOG,ipt_ttl,ipt_tos,ipt_SAME,ipt_REDIRECT,ipt_MARK,ipt_REJECT,ipt_LOG,ipt_state,iptable_filter,ipt_MASQUERADE,iptable_nat,ipt_TOS,iptable_mangle, Live 0xe108f000
rtc 11976 0 - Live 0xe1095000
via_rhine 19336 0 - Live 0xe1082000
8139too 21952 0 - Live 0xe1088000