If your V4L modules fail to load, you might want to investigate the following. Usually, this isn't a difficult problem to solve. Mixed Module Versions Make sure that all of the modules that you load are part of the same package. You'll want to do this for all required modules. Mixing different driver versions is bad and will most likely get you nowhere.
Card Seating Make sure the card is plugged in completely.
Here's what to try if the kernel recognizes the fact that you have a video card, but you can't see any video. I don't know why this is, but in my experience, this is often necessary. Also, don't worry about loosing efficiency. One modules are loaded, they behave just as fast as they would if they were compiled in. Check the Feed Make sure you have a live, and valid video feed.