Thank you, I will, I couldn't find that!
What you describe is a "classic" symptom of a variable frame rate
Exactly what is INSIDE the video you are editing?
Codec & Format information, with 2 links inside for you to read http://forums.adobe.com/thread/1270588
Report back with the codec details of your file, use the programs below... A screen shot works well to SHOW people what you are doing
https://forums.adobe.com/thread/1070933 for screen shot instructions
Free programs to get file information for PC/Mac http://mediaarea.net/en/MediaInfo/Download
As far as I know, the only way to fix a variable frame rate problem is to use some other program to convert your file before editing... or check the settings in the program you use to create the file
The best way to confirm a variable frame rate for your video is to take it into the free video audio properties readout program named MediaInfo using its Tree view.
If the Video section of the readout shows 3 frames rates (minimum, mid-range, and maximum), then you are dealing with a video recorded with a variable frame rate instead of a constant one.
If that is the case, then you use a program like HandBrake to convert the video to H.264.mp4 with a constant frame rate.
Another consideration...assure that your project preset is set to match the properties of your source file. Then the questions become:
a. What are the properties of your source file
b. What have you (manually) or the project (automatically) set as the project preset.
See Edit Menu/Project Settings/General and the readings for Editing Mode, Timebase, Frame Size, and Pixel Aspect Ratio (even if
they look grayed out.)
Please review and consider.
Add On...original was addressed to the wrong ID...post has edited to address reply to craigf.
...wonderful...with my RENTAL FEE I shouldn't have to worry about this crap!
Complain to the capture software developer or the smartphone companies for making them variable framerate (which is uneditable.)