JSON-RPC problem with Bitcoin-Qt 0.8.5
From the Accounts wiki page:


getaccountaddress will return the same address until coins are received on that address; once coins have been received, it will generate and return a new address.
getnewaddress always generates and returns a new address.
setaccount changes the account associated with an existing address. Coins previously received on that address (if any) will be debited from the previous account's balance and credited to the address' new account. Note that doing so may make the previous account's balance negative.


Use the getaddressesbyaccount method to list all addresses associated with an account.