Good stuff man. Just a thought - I would make sure that you don't only compliment them on their looks (e.g. saying they look sexy etc.) Make sure you compliment them on their personality as well (but only if you mean it), if you're not doing it already that is.

What might be happening is that you're coming across a bit like a super-slick player (the question about your previous gf's?). Just a thought. But it doesn't sound like you're doing too much wrong, just the external factors which you have no control over messing up your chances.