Comment 44 for bug 341363

Again, "Error unknown parameter 6" is merely a warning message which pops up in various circumstances, and is not the *cause* of a crash or other problem. Suppression of the confusing warning error message is up to the kernel team. If you are experiencing an X crash, then again I would ask that you report it as a *separate* bug report so that it is simpler to troubleshoot.

For information on creating good bug reports about X problems please see http://wiki.ubuntu.com/X/Reporting, and in particular for crashes see http://wiki.ubuntu.com/X/Backtracing for directions on how to get proper debug output so the issue can be solved.