I have a student with an urgent problem that I can't seem to fix.
The student is making a film having shot it on mini DV tape. He has been editing the film in Adobe Premiere Pro CS5.5, editing sections in different sequences.
The problem he is having is when he moves a selection of clips on his timeline random frames or half frames disappear, leaving a very quick flash to black.
I cant work out why the frames are disappearing when moving clips up and down the timeline, any suggestions?
Sounds to me like your sequence is set to the wrong frame rate for the footage. Check both frame rates in the info panel and see if they match. If they do not, create a new sequence with the correct frame rate and copy & paste the entire contents of the old sequence to the new one.
I agree as well that this is probably a footage interpretation problem. Check the properties of the footage and see whether they agree with the camera's (output) encode specifications. To make sure that you're setting the right sequence settings inside of PPro, see the forum post below which will allow PPro to detect and match the footage's settings.
I have a similar problem. My footage is 25fps AVCHD shot on a Sony AX2000. For some reason, when I created a new sequence, PP5.5 decided that it should be 24fps. I edited five sequences like this, and only noticed the problem when I exported it onto a DVD and there were numerous dropped frames. I've tried creating a new sequence at 25fps and dragging the 24fps sequence into it, but it makes no difference, and I can't find a way to change the frame rate in the problem sequences. Any suggestions would be very welcome.
The settings for a sequence cannot be changed once it is created.
If source footage is being interpreted wrongly, right-click the source file on the project panel and choose Modify > Interpret Footage. You can now create a new sequence that matches the real properties of your footage.
Dragging one sequence into another won't cure the problem; you have to copy the footage from the timeline into the new sequence so it reverts to the new sequence frame rate (assuming the footage has been defined properly in the project panel it will then be correct).