U r ryt and we are using custom PO o/p type.
We have done that analysis already and also referred with OSS note111062 and where it tells us to use the std ones.
As you said i am checking with my abaper and we also suspect two diff users paralley executing ME9F for same PO and landed up with this update termination.
Please share your thoughts on our analysis as well.
Cheers,
Kumar.S