It would not be difficult to replace the bank run with a house drop - but that is not what I would do these days.
If after doing what TG suggests, following the initial post modifications, the ASOS still doesn't work, then you will probably have to step through the logic and see how it evaluates. You could probably toss a regular SOS and an ASOS on the serpent corpse to see if it will pull the ASOS and leave the SOS behind. That would determine if it is the looting logic or the evaluate logic that doesn't seem to be working for you.
That post on page 63, stated that the issue was trying to open the MIB while on the serpent's corpse. In general, that doesn't make sense as an issue. I have a script that opens MIB's in containers that are not my #backpack, so that shouldn't be the issue.
You would have the ASOS chioce checked (but do not need the MIB choice checked) in order to only loot ASOS.
Gaderian