More information needed for someone to help... please click below and provide the requested information
-Information FAQ http://forums.adobe.com/message/4200840
What are you editing, and does your sequence match your video?
For CS5 and later, the easy way to insure that your video and your project match
See 2nd post for picture of NEW ITEM process http://forums.adobe.com/thread/872666
-and a FAQ on sequence setting http://forums.adobe.com/message/3804341