It's pretty much impossible for a large gain in money to make someone less happy, but it's quite common for it to make someone more happy. Just because money doesn't guarantee happiness doesn't mean there's no correlation between having money and being happy.
But if John Travolta started bitching about how much it sucks to be a famous actor because of [insert trivial problem associated with being a famous actor here], I wouldn't have much sympathy because being a famous actor comes with a lot more advantages than disadvantages.
And dude, about the money thing--yeah, having money won't guarantee that you're happy, but it's obvious that rich people will experience a higher average level of happiness than poor people because money confers more freedom to do what you want when you want.
Are there some poor people out there who are happier than some rich people? Sure, but that's not the point--more money obviously correlates with more happiness; just read some basic sociology data. Rich people are happier on average than poor people, case closed.