At LCY, I was told by BA, that the new ALTEA system that most Oneworld airlines use no longer allow thru check in on separate tickets.

I was on 3 tickets. BA from LCY to AMS, CX from AMS to HKG and KA from HKG to PEN. BA would only check it through to HKG - only after my insistence due to their delayed LCY-AMS. They said 'normally' it cannot be done and they won't do it. But since its their fault, they will do it - this one time but they can only do it through to HKG as the new system will not accept another connection. BA at LHR apparently still doing it as their airport systems have not been upgraded yet.

At AMS, CX told me the same thing that yes, due to the new system, that they can only check bags to what is stated on the ticket. No more separate connecting flights. Though he said that its easy with CX/KA transfers.

Yeah...