Bindi Irwin -- 'DWTS' Lowdown ... I'm Getting Paid, and I Didn't Fart!!!

Bindi Irwin has no worry she'll get the money she's owed for winning "Dancing with the Stars" ... despite the fact a judge still hasn't approved her contract.

The 17-year-old was leaving LAX when we asked her about the contract, and sure she'll get the money -- more than $300k, but there's a hitch ... she answers to 2 tax men, not just one. But anything left won't go in her pocket ... she's got a cause.

And Bindi clears the air over the mysterious fart noise during the competition.