Just wanted to reply so there is another curious basenji owner stating they have encountered the same thing. Our basenji, Pharaoh, also burps occasionally. He, at 10 weeks, has vomited once and almost just did for the second time only moments ago.
He was very close to doing so that he became weak and it brought to my memory how he was when he did vomit. He basically blacked-out "for all intents and purposes", he just lost muscle control, went straight legged and rocked over face first into the floor. It was not a pretty/comforting sight, but he seems just fine and as others have stated that it seems due to lack of proper feeding/empty stomach. Pharaoh has been eating the chicken soup for the puppy kibble(whatever the exact brand name is).