Comment 7 for bug 1228570

I am also logging into my Thinkpad Twist via SSH (with "-X" option to be able to use X apps) and indeed this influences whether I can log in. If I am able to log in directly on my laptop's screen, I am able to log in again and again as long as I do not log in via SSH. If I log in via SSH from another machine while I am logged in on the laptop's own screen and then log out on the laptop's screen I cannot log in again on the laptop's screen. To be able to log in again, I have to log out of the SSH session and log in again via SSH, after that I can log in again on the laptop's screen.

My .Xauthority file is most probably the culprit. The laptop's screen is DISPLAY :0, the SSH session has DISPLAY :10 (see DISPLAY variable in terminal). The .Xauthority file has up to three lines. Most is unreadable binary data, all contain "till-twist" (the host name of the laptop) near the beginning, some binary bytes, a number, some more binary bytes, "MIT-MAGIC-COOKIE-1", and more binary bytes. In a healthy (I can log in from the laptop's native screen) .XAuthority all lines have different numbers, usually 0, 10, 11 in arbitrary order, or there are only two lines, also with different numbers out of 0, 10, and 11. A broken (I cannot log in) .Xauthority contains two lines with the number 10 and one with 11.