Some users are reporting a variety of issues after applying Snow Leopard Graphics Update 1.0, which (for the majority of users) fixes longstanding issues with several games and provides an OpenGL performance boost.
Slow/laggy system performane. Some users have reported sluggish transitions between applications, slow scrolling and other performance related issues after the update (again, most users experience a performance improvement).
Inability to playback video on websites. Some users have reported an inability to playback video content on websites after the update.
Graphic artifacts/flickering. Graphic artifacts, including odd lines and flickering have occurred for some users after the update.
Startup failure (blue screen). Some users cannot properly startup their systems after applying the update, receiving only a blue screen that never proceeds to the Finder.
Rest SMC. Some users have reported that resetting the SMC resolves some of the aforementioned issues.
smcFanControl. In some cases, overheating may be to blame–users have reported CPU/GPU temperature increases after the update.The utility smcFanControl, which can control fan speed, has worked to alleviate graphic artifacts and some performance issues apparent after the update. Users report success in setting the fan speed to roughly 5,000 RPM when engaging in graphics-intense activities.
Failing the above, try these fixes:
Option #1 — try this first
Download the Mac OS X 10.6.4 combo updater, which weighs in at a hefty 887MB but is a troubleshooting godsend. Quit all open applications and run the installer.
Option #2 — if option #1 fails, try this.
Booting your Mac in Safe Mode then simply restarting normally is one of the most overlooked, most effective procedures for solving a variety of issues after an incremental Mac OS X update. The reason for its efficacy: booting in Safe Mode forces a disk directory check, clears potentially problematic cache files and performs other routines, detailed here.
To boot in Safe Mode, hold the Shift key while your Mac is starting up. After booting in Safe Mode, simply restart normally (without holding the Shift key) and check for persistence of the issue.
Option #3 — if options #1 and #2 fail, try this.
Downgrade to Mac OS X 10.6.3. Although this option eliminates important security fixes included in Mac OS X 10.6.4, along with any other enhancements, it may be the best option if a problem is interrupting your workflow and options #1 and #2 prove ineffective.
Reinstall (if you don’t have a current Time Machine backup). Insert your Snow Leopard installation disc, then restart while holding down the C key. When prompted, choose the normal “Install” option. Make sure to select “Preserve Users and Network Settings.”
After installation, you’ll be left with an earlier iteration of Mac OS X 10.6.x (most current retail discs include Mac OS X 10.6.2), but an otherwise largely intact system. Download the Mac OS X 10.6.3 combo updater and apply it if your disc has an earlier version of Snow Leopard. You may need to restore some saved username/password information, browser information, etc.
Restore from Time Machine Backup. If you have a current Time Machine backup,connect the Time Machine backup disk, then insert your Snow Leopard installation disc, then restart while holding down the C key. After selecting your language, go to the Utilities menu and choose”Restore from Time Machine Backup.” Choose your Time Machine backup disk and choose a backup iteration directly prior to when you installed the Mac OS X 10.6.4, and continue with the process.