I've found Chrome & Chromium have issues with system title bar and borders (option) that appears only relevant to Xfce. Using (in terminal): chromium-browser --app=http://www.google.co.uk (or google-chrome) For example, will open a new window to Google; this window should open maximised but it doesn't, yet it appears that Xfce believes it has opened maximised as the window menu gives me the option to "unmaximise", which, when clicked, does nothing but change that option to "maximise", which, once clicked, does maximise the window correctly. I've tested this in Fedora 18 (Xfce), Xubuntu 12.10 and 13.04 and it doesn't work properly in any of them (but Ubuntu 12.10 Unity/Fedora 18 Gnome all work properly, maximising the window upon opening, thus cannot be a chrome/ium issue). Opening the browser normally (without the "--app" flag or system border setting) maximises the window (remembered state) as usual. Upon further investigation, it appears that enabling the 'system title bar and borders' option, regardless of the --app flag, will open the window unmaximised, with the option to "unmaximise", therefore I assume Xfce believes it has opened the window maximised.
This bug also affects Firefox, which can be replicated by going to http://markets.ft.com/research/Markets/Tearsheets/Summary?s=LLPE:LSE and clicking on the "Historical prices" link. It opens in a new window that Xfce believes is maximised (due to the "unmaximise" option in the window control) but is opened un-maximised.