Replying to Help with exporting from FCE?

newb question: So I just got FCE and its working well, but I'm a little lost on the exporting. The problem is that there are a bunch of little lines in the exported vid. it seems like no matter what settings i use its either a small file with all the lines or a huge file without them. A lot of people say deinterlace, and I've tried, can someone explain this more?
Basically how should I export so I dont have those annoying lines in my video? I'm trying to get the best quality for uploading to vimeo and such...