NBA Players With Money Trouble, Exhibit B
There are lots of off-the-record stories about stuff like this.
And a few on the record, like the story the other day including allegations that after a few years in the NBA, Nene had a negative net worth.
On his blog, the Washington Post's Ivan Carter has similar tales about Andray Blatche:
I heard from a good source that the kid was sleeping at Verizon Center for several nights as rookie because he couldn't pay rent ... I had a conversation about Andray with a player recently and the player nailed it: "He's wild with the money he has now so what's going to happen if you give that guy millions? I have no idea what's going to happen but it's gonna be interesting."