Nope, it had nothing to do with money. Vieri got very upset when Italy won the world cup which hie missed through injury, and then got injured again.
He flipped, there were reports that he had a nervous breakdown. So he failed to turn up for training with Samp (he had signed a contract with them in July, so there were no money problems with them) and hinted that he was thinking of retiring.
He left Samp waiting without even knowing if they should buy another striker. When he decided to go back, Samp knew better and told him to get lost.
Then he was linked to a move to Saudi Arabia, then JuBe. Now it's Atalanta. If he doesn't sign for anyone by 30 August he won't be able to play until 2007.
In the middle of all this 'crisis', Vieri still managed to negotiate a TV deal to appear in some reality show, which in the end he turned down since he wasn't getting paid as much as he wanted. He also managed to get himself in the papers while hanging around with his mates and girlfriend, first in Milan, then in Sardegna.
He is now asking Atalanta to sign him, guess why... cause if they do, he won't have to move house, he can still live in Milan... these are this man's priorities.
By the way, if you don't believe any of this, I'll be more than happy to look for the original sources, but it's all true.