As far as I know, Captivate HTML5 is "not tested and approved for Android devices". That's been the official answer from Adobe to other threads about HTML5 and Android. It's their way of saying: "Don't be surprised if it doesn't work."
My personal observation is that Adobe is more focused on getting Captivate HTML5 to work on iPad at the moment because it has the greatest market share of tablet devices. The Android browser will likely get more attention in future.
