I set up a listener to dynamically change a store's URL based upon an item selected in a ListView (backed by a different store). The store's URL is originally set via it's proxy so I assumed that that was where I needed to change it (i.e. store.proxy.url). Finding this not to work and doing a little digging in the forum, I decided to try store.proxy.conn.url instead and it did work. Debugging via Firebug showed that store.proxy.conn.url was null prior to being set in the listener and store.proxy.url still had the original value after the change to store.proxy.conn.url. Even though it worked, I was still puzzled by this behavior and was hoping that someone could explain it.