I have the exact same issue.Logging out of my charachter and then selecting quit from the charachter selection screen doesn't help at all.Exact same thing happens as mentioned I have a black screen with the game's mouse pointer in the middle. It takes forever to go back to the desktop.Tried hiting alt+tab,alt+esc,windows key,ctrl+alt+delete to open task manager,nothing speeds up the process.Quite often I have to reset my computer to exit the game,simply because i don't have time to wait that long for the game to exit properly.