I have added a couple of comments on bug #919437 since it seems related. Digging it seems like the Compiz session management plugin may be to blame for windows that don't appear on first launch. My comment about this on bug #919437
If you install CompizConfig Settings Manager and disable the Session Management plugin (under Utility) then your windows will return after you log out and back in.
It seems that the session management plugin can return invalid data and Unity expects it to do the right thing.
I have still had windows vanish, normally Software Updaters automatic run, but restarting the application now always fixes it with the Compiz session manager disabled.
I have added a couple of comments on bug #919437 since it seems related. Digging it seems like the Compiz session management plugin may be to blame for windows that don't appear on first launch. My comment about this on bug #919437
If you install CompizConfig Settings Manager and disable the Session Management plugin (under Utility) then your windows will return after you log out and back in.
It seems that the session management plugin can return invalid data and Unity expects it to do the right thing.
My guess is that http:// bazaar. launchpad. net/~compiz- team/compiz/ 0.9.12/ view/head: /plugins/ session/ src/session. cpp SessionScreen: :readWindow needs some sanity checking as do the state load and save functions.
I have still had windows vanish, normally Software Updaters automatic run, but restarting the application now always fixes it with the Compiz session manager disabled.