The meanings are almost the same and you can choose. There is a slight difference of emphasis e.g. I saw the thief steal the car [the completed action - the successful theft of the car] I saw the thief stealing the car [the activity of stealing - what the thief was doing]

I think the difference is same as between do and doing themselves. I mean you can "see that sb do his homework regularly" and "see sb is doing his homework at the moment". I'm not native English speaker so I might be wrong of course. Regards