Mac OS X 10.6.3 has worked out fairly well and my living room carpet has yet to spontaneously catch fire as a result of installing it, but an ongoing issue with the operating system version seems to corrupt graphics on external displays when you present in full screen with “mirrored” displays. In routine situations, the display will work and show the mirrored desktop in the Finder, but when applications take over use the display to show full-screen presentations, media, or other purposes, the graphics will garble and can only be fixed with a restart.
Per CNET, this problem seems to happen on multiple machines, though MacBooks are more prominently affected. This is probably because they are used more for presentations. Users have tried SMC resets, PRAM resets, and numerous approaches to clearing caches, fixing permissions, running other maintenance routines with no luck.
Over on the Apple Discussion Board, chatter between a number of has indicated that the problem could be a bug in the latest OS release, which updated the drivers, OpenGL, and other graphics technologies.
If you are affected by this problem, you can use one of the following work-arounds to keep your display from corrupting:
“Try a different video processor:
For MacBook Pro owners who have multiple GPUs in their systems, the problem may be avoidable by switching the graphics processor being used. To do this, go to the “Energy Saver” system preferences and change the option from “Higher Performance” to “Better Battery Life” or vice versa.
Use extended desktop:
Instead of using the mirroring mode in OS X, change the external display to be in extended desktop mode. Do this by going to the “Displays” system preferences and unchecking the box to “mirror displays.” Once this has been done, to use your presentation, just drag the window to the desired display and activate it (should work in PowerPoint and Keynote).
Make a presentation boot drive:
Make a presentation boot drive if you have an external drive. Install OS X to it and upgrade it to 10.6.2, and install your presentation software to it. Then when you are giving a presentation just copy your presentation to that drive, reboot to it, and run your presentation in mirrored display mode without the display problems.
Move back to 10.6.2:
The last step is to move your system back to OS 10.6.2, which can be done by restoring to a previous Time Machine backup. It can also be done by performing a reinstallation of OS X from the Snow Leopard DVD. The installer will create an “Archive and Install” of the system that should keep as many of your settings and application installations as intact as possible, but do be sure to back up beforehand as an extra precaution.
Rumor has it that Apple has started issuing developer releases of OS 10.6.4 already, so hopefully the update will address these issues.
If you’ve seen this issue from your end, please let us know about it.
2 replies on “Users report mirrored display bug in Mac OS X 10.6.3”
I am the president of our local Mac user group, and we had a SIG meeting at a Member's home last Thursday, and ran into the same issue, when connecting his Mac Pro to his Sony Widescreen in Mirror Mode. We cold get the Widescreen or the Apple display to run at the primary display, deepening on switching the connections, but not both. He is running 10.6.4, so the bug persists. Booting into Windows 7 via boot camp allowed both mirror and extended modes on both displays, so that shows it is a system issue.
Ditto here. How embarrassing that the PC actually worked better:(