Checksum Errors when analyzing hp-ux traffic

Hello,

When analyzing traces collected in hp-ux using the command "nettl",
ethereal shows it as a bad checksum, but looking the same frame in the
hp-ux sing the command "netfmt" the checksum is ok.

I work for HP and I cannot duplicate this problem with my system,
including analyzing some traces that the customer has sent to me. In my
PC running windows XP, I can see the checksum correctly, but the same
file at the customer displays "bad checksum". I have already also the
customer to update the version of ethereal, but it didn't solve the
problem. I can read the same file in many systems, with no problem, but
the customer is able to duplicate it on many systems also.

For sure, if in the native hp-ux system the checksum is ok, the problem
should be at ethereal, but I have no idea what else I can do to try to
help the customer.

Do you have any about this problem?

Regards,

Luiz Sergio