[Mary Hansen]

I have almost this exact same problem.

Mostly I’ve been working with videos that have a run-time of less than 10 minutes and are less than 1 GB in size, and they all run fine in the preview and source panes of Premiere Pro CS6.

I recently imported a 3.6 GB file of a one-hour video, and it runs fine in VLC, QuickTime, WMP, etc. But in Premiere, it runs fine for about three minutes, and then the audio and video get progressively further out of sync, with the video eventually lagging about four seconds behind the audio.

My computer’s specs:
Windows 7 Enterprise SP1, 64-bit
Processor: Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz 2.40GHz
RAM: 8 GB
Video card: Nvidia Quadro 3000M (I have more info for this like Driver version: 276.05, Processor clock: 900 MHz, etc.)
Hard Drive: Seagate Momentus ST9750420AS 750GB 7200 RPM 16MB Cache 2.5″ SATA 3.0Gb/s Internal Notebook Hard Drive
Software: Adobe Premiere Pro CS6 6.0.3

My 3.6 GB video’s specs:
MSNV: MPEG-4 (.MP4) for SonyPSP
1280×720
Audio Codec: mp4a: MPEG-4 AAC LC, 44100Hz 131 kb/s tot , stereo (2/0)
Video Codec: avc 1, H.264/MPEG-4 AVC
Frames/s: 30.000

Things I’ve tried:
1. Running my laptop without any additional screens
2. Running Windows with the “Best Performance” settings
3. Using an external hard drive as a scratch disk

Things I might need to try:
1. Reinstalling Premiere (My IT dept. has the software and reg. key, so I’d have to go to them)
2. Updating my graphics card driver (This looks complicated, like I could add a driver for ODE graphics or Performance, etc., but I don’t know if I should pick one or all)

Any recommendations on next steps?

Thank you!