I'm an atheist but I quite like Buddism...

[One Above All]

A lot of folks here post about not liking the karma concept, I guess I drew the idea of karma as a scientific principle much like cause and effect. Its an easy idea to understand, if I act in a good way towards people its likely to have the effect of having them reciprocate.

Karma is a supernatural concept. There's about as much science in it as there is in any other religious idea.
The original concept, as I understand it, was that good and evil existed in equal amounts and intensities. If you did something good, shit happened elsewhere (maybe even to you) to "restore the balance" or some other crap like that.
The current idea is that if you do good, good stuff happens to you. This, however, has several assumptions, namely absolute morality and the idea that, somehow, the Universe as a whole gives a shit. This is not a "selfless" type of quid pro quo. This is something like "You helped that old lady cross the street" leading to "You won the lottery".
The current concept of karma also has the connotation that, whatever bad things happen to you, you and you alone were directly responsible for them.