Old style dual head setup with two xservers on a  dual headed video card :0.0 and :0.1.
 Some apps appear to not be able to find the secondary display and only register in put or display outputs on the primary display.


Example one:

_Expected: Java applet to appear in browser window.
When loading a Java applet in a browser on the primary display the expected applet appears in the browser and works as normal.

When loading the same applet in a browser on teh secondary display it leaves a blank pages and outputs the following Java Plugin failure to the console:
java.lang.ExceptionInInitializerError
	at sun.plugin.JavaRunTime.initEnvironment(Unknown Source)
	at sun.plugin.navig.motif.Plugin.doit(Unknown Source)
	at sun.plugin.navig.motif.Plugin.start(Unknown Source)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 1
	at sun.awt.X11GraphicsEnvironment.getDefaultScreenDevice(Unknown Source)
	at java.awt.Window.init(Unknown Source)
	at java.awt.Window.<init>(Unknown Source)
	at java.awt.Frame.<init>(Unknown Source)
	at java.awt.Frame.<init>(Unknown Source)
	at sun.plugin.AppletViewer.<clinit>(Unknown Source)

Example2:
_Expected: As long as system in use xscreensaver stays off
When working only on the secondary display the xscreensaver idle timer will time out the xscreensaver will kick in. When working on only the primary display xscreensaver stays off. When working on both monitors xscreensaver stays off.

Example3
_expected: Tomboy to open on the same display as the cursor and applet.
When applet and cursor are on primary display it works as expected.

when Applet and cursor are on the secondary display it opens on the primary display instead of the secondary display. 


This was tested with JRE 1.5 and 6, firefox 2.0.0.4-11, epiphany, and seamonkey browsers. Each was tested in both gnome and windowmaker. The setup worked under  Xorg 6.9 as expected on both displays but not 7.2