[Mientras]

I’m running After Effects CS3 (8.0.1) on a quad-core Mac Pro with 5 gig of RAM. In addition to being unable to import numerous mpeg4 QuickTime files, I am also unable to open AE 6.5 files that use such mpegs. Oddly, my old iMac G5 (PowerPC) running AE CS3 can perform both tasks. For reasons of speed and efficiency, I obviously would prefer to work on the Mac Pro. Even when running CS3 in Rosetta on the Mac Pro, import and file opening problems emerge.

I’ve trashed preferences, uninstalled and reinstalled QuickTime, trashed all potentially conflicting plug-ins, checked my fonts, even uninstalled and reinstalled CS3. All that is left is a troubled wringing of the hands.

[Mientras]

I’m having the same problem. Very frustrating. I’m running AE CS3 on a quad core Mac Pro (Intel) with 5 gig of RAM. Large m4p files are giving me fits. Curiously, they import fine on my slower iMac G5 (PowerPC), but I would REALLY prefer to work on the faster machine. Another oddity is that while AE CS3 imports the problematic files on the iMac G5, the Mac Pro cannot do so even when using PowerPC emulation (a la Rosetta).

I’ve done all of the suggested stuff (trashed preferences, checked fonts, trashed the plug-ins folder, trashed and reinstalled QuickTime, reinstalled AE CS3 itself)