I wouldn't agree with a generic statement that it is "very common" and I have no idea what "balance of payments issues" have to do with it.
I think most people's recent experiences (mine, certainly) has tended to be that if QF (or BA or CX etc.) shows award availability, then it's available via AA. Certainly, there may be exceptions but not to the level of saying it's "very common". AA certainly has difficulty sometimes 'seeing' award availability that is, in fact, there. I had two recent experiences of this (one, LHR-SIN-MEL in F and the other CNS-BNE-CBR-MEL in J, the latter a somewhat convoluted routing) where QF (and BA for the LHR-MEL one) showed it as available but AA insisted it was not. After much persistence (including one idiotic EXP agent who insisted that "you obviously must be looking at revenue ticket availability"), the award seats were, in fact, there via AA.
In this case, QF shows award availability in Y every day in May - and 19 out of the 31 days in May are available direct (LAX-LIM) on LAN and the other days on AA via MIA. I suspect (but have no knowledge one way or the other) that AA may not make the direct (LAN) flight available and thus forces you to take the AA flights via MIA. QF has no incentive to do that as they don't fly the route so will presumably make the LAN flight available to its members if LAN is prepared to make it available, whereas AA may be inclined to force you on to its flights, even if LAN is prepared to make the award inventory available. I have no experience of LAX-LIM (or LAN) so perhaps others who have can comment further.
hi tt7, thanks for the response. That's sort of what I'm suspecting as well... AA not making the flights on LAN available. If I go search on the QF website, there are literally tons of availability on the LAN LAX-LIM flight... but the 5-7 AA CSR I spoke too couldn't see any of them.
I actually asked one lady if the awards flights made available by LAN can be seen by all OW airlines... and she said she doesn't think so because LAN may "give" a number of award seats to each airline separately. So if AAdvantage members already redeemed those LAN flights, we won't be able to redeem additional award flights seen on QF, CX, etc... I don't know the accuracy of her statements, but it does seem a little strange.