There are a lot of reasons to donate money to a cause: tax write-offs, guilt, religious beliefs, security, and compassion are just the first the come to mind. Some reasons are self-serving and others are not. Here is a case of what looks like the self-serving kind.
It appears that Bill Clinton traveled to Kazakhstan with a mining executive, met with Kazakhstan's authoritarian president, said really nice things about him, got the mining executive a hugely profitable uranium mining contract, and then received a $131 million donation for the Clinton Foundation.
It's tough to know the details, Clinton has been to Kazakhstan before to discuss cooperation on HIV, so his relationship with President Nazarbayev is based on more than just politics. But the whole thing looks pretty skeezy.
Most NGOs don't have the political muscle to do something like this, but the ethics of how far you go to please private and public donors is one that everyone faces. This is pretty clearly over the line. The Clinton Foundation should be trying to stand for something, and not just rest on the personal connections and charisma of its founder.
At the same time, I don't know how much harm was done. All Clinton said was that he supports Kazakhstan's bid to be president of the Organization for Security and Cooperation in Europe (OSCE). He doesn't make that decision. As far as I know he has no direct influence on that decision. He might have given Nazarbayev some domestic credibility, but he's got Kazakhstan so tied down I don't think that makes much difference.