I've found a topic on the Diablo forums saying the AH is bugged. Sometimes it just can't access the database and it shows it as empty. I'm on north america by the way.

I guess that answers the question

I think it's just that the AH is extremely laggy. That's why sometimes it shows items, sometimes it does not.

I think you're right indeed. Just now the list appeared once then it's gone again >_<

timeout = no results found.

just a wild guess

i normally will use buyout, if buyout too high then i will just skip to the next item, normally ppl will use buyout cause they can use the item instantly, if you set buyout price too high, ppl will forced to use bid and bid they can only use the item days later which normally ppl dont want to wait, so they will just ignore the item most of the time.

mostly bidding is for those uber tier items.. no people would be 'smart' enough to bid for a lower-mid tier item since they're easily replaced, unless it is really underpriced