The comments here were a little sharp, but in general correct. Most likely the fact you own a house right now is the reason. I am sure HLS will be able to me more specific.
Our situation is somewhat similar, though we don’t have your great income, and we only have 10% down (but we are looking at 500K houses). And probably much leass money aside. But the main difference is, we don’t have any debt. We owned a 3 bdr townhouse until Fall 2007 and we are renting a nice large 2 bdr apt since then, waiting for the air over the house market to clear. It’s a bit tight, but it’s worth the peace of mind. Anyhow, the point is, we would be able to get a 500K loan with 10% down. Of course with PMI. A 2nd loan apparently it was almost impossible to find. I am sure you could get easily a loan for under $546K (or whatever was the limit) with your income.
I think HLS would be a great help here. The only solutions are
1.sell your current place and rent at least for a short while until you can buy a new place.
2.if that’s too much trouble – wait until you have or are willing to put 20% down; the prices will decrease more by then too.
3.if it’s really urgent to move now, then put 20% down – you seem like you have other savings and you could do that. See if you can get a loan then. You should be able to, IMO.