Ok, after much futzing around, following some of the advice here and elsewhere, I've finally found the knack to getting this thing to seal.
Whether these are all completely necessary or not, I don't know, but now that it's working, I'm not messing with success:
1. Manual says three-inch headway on the bags, I'm using four.
2. Set the bag on a book to lift it up to be more even with the opening of the machine, which lessens the likelihood of bending/crimping the bag.
3. Make sure the bag is placed textured side up and smooth side down.
4. Get it positioned exactly, and I mean exactly, on the top edge of the gasket that goes round the drip tray. A hair's width off up or down, and it ain't working.
5. Raise your left foot, cover your eye with your left hand, turn around once, and say, "I command thee, seal my meal!"
Well, it shouldn't be that hard. It certainly isn't for me. The book thing is a little weird. If I understand "headway," I don't think you need that much -- every time. If the food is very wet, you may need that. In that case, do what Late Nite suggests, and freeze your food before vacuum sealing it. I do that with peppers from my garden, so they will be hard before I vacuum seal them. That keeps them from being squashed under vacuum.
I still think your Foodsaver ain't quite right. I know mine works much more reliably than what you have experienced. It really shouldn't be that difficult. Mine sure isn't.
CD