Changing screen geometry in the middle of startup messes up positions of autostart application windows

Something during the startup of Unity messes up predefined positions of autostart applications. Debugging the issue resulted that when "DEBUG 2011-12-14 01:51:42 glib <unknown>:0 Setting to primary screen rect: x=0 y=0 w=1280 h=1024" was displayed after the autostart application was started/displayed, then at least one of the predefined coordinates (x or y) of autostart application window was messed up (set to default value).

The message displayed in ~/.xsession-errors is defined in UnityScreen::Relayout in plugins/unityshell/src/unityshell.cpp and it seems that if I run my applications after that message is displayed during Unity startup, there are no problems.

However, this is not expected behaviour from Unity shell, it shouldn't matter when exactly I start my applications, as long as I start them from Ubuntu system menu in a normal way. Unity 2D, GNOME3 shell and GNOME3 fallback session are doing fine in this respect.

Unity version: 4.24.0-0ubuntu2b1

See also: https://bugs.launchpad.net/screenlets/+bug/885322