Excerpts from Leo Alekseyev's message of Sat Feb 11 18:22:03 -0700 2012:
If anyone has advice on how to reset Xmobar without Xmonad restart (or at least how to make the Xmonad restart not touch my window config), I'd love to hear it!
I believe the newer versionns or possibly only the latest git xmobars adjust to screen reconfigurations on the fly. Disclaimer: haven't run xmobar in a long while, and no clue if tablet orientation changes are different from normal xrandr xinerama screen changes. As far as restarting, mod-q should only change window arrangement if you've significantly changed the layoutHook in xmonad.hs. Normally all the windows and workspaces remain as is. You aren't by chance using mod-shift-q which would log you out of X11 are you? Regards, W