I'm trying to get my display working in portrait mode and having used the handy option on the display resolution screen to rotate it the way I wanted (BTW I don't find the idea of rotate left or right very intuitive, do you mean rotate the bottom left or the top left). Anyway now when I log in the X server hangs for ages. Sorry, I don't have an exact time, the monitor just switches back to the other system attached to it. If I leave it for an hour or so and then come back it has succeeded in starting and the screen in running fine.
Anyone have any ideas?