Default [Q] Optimus 2x external_sd

Hello everyone,
I have an Optimus 2x (rooted) and I want to move or install apps to an external sd (\external_sd). I tried with set-install-location 2 e with app2sd but they both move the apps only between the phone and the internal sd (\sdcard)...I think these aren't functioning because of memorie's names. Is this correct? Is there a way to change the names?