QuickTime 7.5 (#2): Slow, choppy playback; startup issues; crashes; more

Fixes for the most pressing issues affecting this update.

CNET staff

Sept. 2, 2009 2:38 a.m. PT

3 min read

Slow, choppy playback Several users have reported degraded media playback quality after updating to QuickTime 7.5. MacFixIt reader Adrian writes:

"Installed (the update) immediately. Unfortunately, all of my QuickTime content appears to be playing back at 10-15 frames per second even though the Inspector says it's playing at full speed (29.97 fps). Very 'steppy.' Everything was fine with QuickTime 7.4.5. on an iMac G5."

Joe Carson adds:

"i just installed QuickTime 7.5 onto my 1.8 GHz G5 iMac. The video playback is noticeably much slower and jerkier than before. Even a 480 vertical pixel widescreen QuickTime movie from the BBC is failing to run well. The previous versions of Quicktime ran this one very smoothly."

Finally, one reader writes:

"The QuickTime 7.5 update has destroyed its ability to play the 720P previews in my 1.8G PPC/ 1.5MB ram; 500G disc running Leopard 10.5.3. Audio precedes video by an annoying amount and video is presented as just a series of stills rather than smooth video as with previous versions. Thumbs down."

The first thing you should do when experiencing similar issues is check in the following directories:

/Library/QuickTime
/Library/Internet Plug-ins
~/Library/QuickTime

for any third-party add-ons that could be interfering with playback. Remove any third-party items and restart then check for restored playback.

Disable Perian It appears that the presence of Perian, a free, open source QuickTime component that adds native support for many popular video formats. Try removing this software if you experience crashes when attempting to playback certain files.

System startup issues Some users have reported problems with startup, particularly an inability to login, after updating to QuickTime 7.5. Michael writes:

"I just updated my Mac mini (PPC) to QuickTime 7.5 and now the computer will not get past the login screen. I enter my Admin password and it attempts to go further and gives me the blue screen, then just returns to the login screen. Rebooting does not solve the problem."

The recommended procedure is to simply boot in Safe Mode -- accomplished by holding down the Shift key while your Mac is starting up. After the safe boot, restart normally. A number of maintenance tasks are performed during the safe boot, and you might not need to perform any additional troubleshooting. You might receive a message indicating that the update has finished installing after performing the safe boot.

Failing the aforementioned, peruse our tutorial titled "Startup fails (particularly after a system or security update); solving." One of the solutions listed there -- including delete specific caches, rooting out problematic kernel extensions, repairing drive damage, and disconnecting external devices -- might prove successful.

If worse comes to worst, you may need to resinstall the system (even though reinstalling the system isn't that bad), via our tutorial.

Sound missing Some users have reported that sound is missing from certain file formats under QuickTime 7.5. One reader writes:

"Upgraded my PowerPC Mac running 10.4.11 to QT 7.5 via software update. Lost sound in existing .flv movie clips."

Problems with external devices A number of users have reported issues with various external devices after updating to QuickTime 7.5.

MacFixIt reader John McD reports an issue with a printer/copier/scanner from Kyocera:

"I am on an office ethernet network to printer/copier/scanner by Kyocera. Up until today, no problem scanning from copier to my mac, via KM ListenerX (opens terminal). Now, the copier no longer recognizes my mac on the network. I can print TO the copier, but can not send from copier to mac. I must assume is has something to do with the many security changes in 7.5 that close off my mac from outsiders."

Ian Ferguson reports issues with his Apple aluminum keyboard after the update: