The bug is still there.
SEA-LAX 12/10/09
LAX-LAS 12/10/09
LAS-SEA 12/15/09
I see only Hot Deals and FC for the AS operated SEA-LAX flights.
LAX-SEA is operated by AA, so only partner fares are visible.
I see only Hot Deals and FC for the AS operated LAS-SEA flights.
If I try booking LAS-SEA on its own, I see fares in all classes.
If I substitute PDX for LAX, I see fares across all classes (on SEA-PDX, there's only Bargain/Value/Full Flex, which I assume is normal for a horizon route).