[Openswan Users] Tx checksum offload (Hardware Checksum) problem in KLIPS (Openswan 2.4.4)

[openswan]

Hello,

I used Openswan 2.4.4 and kernel 2.6.12.6 with KLIPS patch and
everything is ok. The clients that use this VPN connection are mostly
(WINDOWS 2000 Workstations and Linux Workstations). They have installed
ethernet cards 3COM 3c509 and VIA RHINE.
When I tried to activate "Tx checksum offload (Hardware Checksum)" on
these ethernet cards all packets that passed the Openswan (KLIPS) became
delayed or dropped (maybe with invalid Checksum!?). When I deactivate
this option i.e. the IP Stack to make the CHECKSUM everything is working
fine.

Note: When the packets don't pass the Openswan(KLIPS) although the
option "Tx checksum offload (Hardware Checksum)" on clients is activated
packets are not delayed or dropped i.e. the problem is not in the kernel
code maybe.

Can you tell me is this a bug or a feature that's not supported by
Openswan and if there is the same problem if I use Native IPSEC not KLIPS?

Thanks in advance
Nikolay