Per Harm's "Suggestions" link, please tell us about the following:
You Assets. These are the media files that you are working with. Please give ALL details of these: Frame Size, format/CODEC (if Captured from a camera, give make and model), Frame Rate, and everything else.
Your Project. Give the complete settings that you established for the Project/Sequence. These should match your Assets perfectly.
Your Export. Give all of the settings that you are using for this.
The quality loss will be in those details. As Harm points out, we cannot begin to guess as to where the mismatch/problem will be.
Okay, well I was usually just choosing the NTSC Widescreen when creating a project and pressing okay...but I can tell you the video I'm importing is a .mov file created from a flash animation.
the size of the video is 1280x760...I don't know much more what to say. I just need to know how to create a project in Premiere that is also 1280x760, and retains the quality of the video when exported to quicktime format.
It's been a bit, since I last worked in Flash (about Studio 8), but can you not Export as something besides MOV. Also, did you use the Apple Animation CODEC?
Now to your Project/Sequence settings. Create a New Sequence and choose Desktop for the Mode. Set your Frame Size, and FPS to match your MOV. Do note that the Animation CODEC is tough to work with.
The changing of your settings might get you to editing, or you may need to Export with different settings from Flash.
Good luck, and let us know how it works out,