Audio Sync Offset (or just lack of sync)

Hello! I´m having some trouble and audio issues.

I import one video file (.mov, H264, 44.100 khz, AAC)... and then I drop it down to the timeline.

Its audio is out of sync, just a few frames off. But the STRANGE THING IS that:

_If I move frame by frame with the left arrow, the sound that I hear matches de waveform (For example the clapperboard) BUT If I just press play and let it run it automatically goes out of sync, like if the waveform didn´t match the sound, causing my video to seem a little frames ahead, but when I export it.... it´s just fine....

In pro tools I would touch VIDEO SYNC OFFSET to correct the latency or delays between video and audio... but here what should I do?


Thanks

Because it's 44.1 AAC. 44.1 is not a video standard. Where did this come from? Convert the file to QuickTime with uncompressed 48k audio. You can use Compressor or MPEG Streamclip.

Thanks for the quick reply.

I´m gonna try that, but I seriously dbout that´s the issue... because it seems that it´s happening to all my videos. including the ones with aweful sound from youtube...


I´ve recently changed my ram to 8gb DDR 1333 mhz. I used to have 2gb DDR3 1333 mhz and it worked fine... this is the first time I´m working with FCPX with my new ram and this happens...

could a bad ram cause that sync offset?

"could a bad ram cause that sync offset?"

No.

Do you use an external sound card or audio interface?