When I rotate my display during my session using xrandr --output HDMI-1 --rotate left the maximisation of my windows are broken. They won't get higher than the original height of the unrotated display (i.e. a 1680x1050 monitor, after turning becomes 1050x1680, and maximised windows will be at most 1050 in height, not 1680, if we ignore panels for the moment). Things do work fine if I start with a rotated screen by executing xrandr as an autostarted app. However, in that case, when I rotate back, maximising the window won't make it wider than 1050 (the width of the display before rotation). I'm using a full-width xfce4panel at the bottom of my screen, by the way.
Can you try without any panel? xfwm4 is xranrd 1.2 aware but the xfce4-panel is not...
Can you also confirm the version you are using (xfwm4 --version)? I tried and it works fine.
Behaviour does not change when panel is removed or omitted at login. I'm running: This is xfwm4 version 4.4.3 (revision 28474) for Xfce 4.5.93 Released under the terms of the GNU General Public License. Compiled against GTK+-2.14.4, using GTK+-2.14.5. Build configuration and supported features: - Startup notification support: Yes - XSync support: Yes - Render support: Yes - Xrandr support: Yes - Embedded compositor: Yes - KDE systray proxy (deprecated): No On Ubuntu jaunty, morphed into "Xubuntu" manually. My xrandr setup is: Screen 0: minimum 320 x 200, current 1050 x 1680, maximum 1680 x 1680 VGA disconnected (normal left inverted right x axis y axis) LVDS connected (normal left inverted right x axis y axis) 1280x800 60.0 + 40.0 HDMI-1 connected 1050x1680+0+0 left (normal left inverted right x axis y axis) 473mm x 296mm 1680x1050 60.0*+ 59.9 1280x1024 75.0 60.0 1152x864 75.0 1024x768 75.0 60.0 800x600 75.0 60.3 640x480 75.0 59.9 720x400 70.1 HDMI-2 disconnected (normal left inverted right x axis y axis) TV disconnected (normal left inverted right x axis y axis) (the laptop screen LVDS is not used in this setup).
This is xfwm4 version 4.4.3 (revision 28474) for Xfce 4.5.93 ^^^^^ => You are not using xfwm4 from 4.6 Support for xrandr 1.2 will not be backported to 4.4.x