iptables kernel 2.6 and ip masquerade

Hi ,

I have a mandrake 9.2

I used the kernel 2.4.22 and the "ip masquerade" function. Everything was
fine.
I tried the kernel 2.6.test5 but i can't use masquerade anymore :
when i try to setup the rule :

iptables -A POSTROUTING -t nat -o ppp0 -j MASQUERADE

I've got : :

iptables: Invalid argument

I think that all modules are loaded :

Module Size Used by
ipt_MASQUERADE 4352 0
ipt_state 2048 0
iptable_filter 2944 0
ip_nat_ftp 5104 0
iptable_nat 23340 2 ipt_MASQUERADE,ip_nat_ftp
ip_conntrack_irc 71476 0
ip_conntrack_ftp 72116 1 ip_nat_ftp
ip_conntrack 30384 6
ipt_MASQUERADE,ipt_state,ip_nat_ftp,iptable_nat,ip _conntrack_irc,ip_conntrac
k_ftp
ip_tables 18944 4
ipt_MASQUERADE,ipt_state,iptable_filter,iptable_na t
ppp_async 12160 0
ppp_generic 32656 1 ppp_async
slhc 7296 1 ppp_generic
ne 9360 0
8390 10880 1 ne
supermount 40084 1
ehci_hcd 34948 0
uhci_hcd 33292 0
rtc 13368 0

I don't understand

Does anybody have an idea ?

jauss