Again, that all depends on your definition of 'combustion'. As I know that steel wool can combust in an atmosphere of chlorine gas. (Here's where sematnics becomes a real pain in the ass when trying to define something).
To really sum it up:
If you define 'combustion' as a chemical reacion with oxygen, then no, water cannot combust/burn.
If you define 'combusion' as a chemical reaction with a strong oxidizer, then yes, water can combust/burn.