Is it possible to run more than one Bitcoin client at the same time on the same machine? I tried to set different working ports, but it seems not to be working.
You need both a different RPC port (
-rpcport), a different P2P port (
-port), and a different working directory (
-datadir). You will also need to use the daemon (bitcoind) for everything after the first instance, since only one GUI can be running at the same time.