What am i doing wrong?

I've duped twice out of like 100 attempts now. Can someone tell me what i'm doing wrong?

1. Log into A
2. Log into B
3. Wait for screen B to say "connecting..Connected!" and then go into nexus with A
4. Screen shifts to B. B is in the vault, Screen A is still trying to connect to vault.
5. Drag items from chest into inventory.
6. Wait for the Connected! sign on screen A
7. CTRL+Q as fast as the human nervous system will go

try to alt-f4 at connecting, and later on the red letters...

i found out:

- if i dupe on a laaaagge server like asia, us... etc i have to alt-f4 1/2 sec after connected.

- if i dupe on eusouth [best server] i have to alt-f4 at connecting