If I am not mistaken... You can always give reputation points when you like to give them. For example a verry good comment on something (in discussions) or the helping of others with problems.
It is generally meant to thank people for their comments/suggestions/work. Anything you appreciate you can give reputation points... But it also go's the other way around. If it is pure flaming then they can always take points away.
But you will get some points eventually ;) It just takes some time. If I could +rep you then I would do that, but since I am at 9 rep I can not give you any points. I do not have rep power. (look at the main page on the
www.nihonomaru.com)
So that is the thing I am experiencing. I have no idea if it is correctly, but rep does not mean a thing. Trust me. It is nice to get +rep. But eventually it does not make a difference. Good people give rep on a day to day basis. But some people never +rep anyone. So just dont mind it. And if you really want +rep then just ask some1 that has a high reputation. If you are good to others then they are also good to you and you will get +rep if you ask for it. Most people do not seem to know how the reputation works....... :P