Storyboard transitions on kindle fire different to simulator

I have a simple test app that uses storyboard and has a sliding transition from mainmenu to gamescreen.

On the simulator, this works as expected. On kindle fire, it only works properly the first time. The second time, the old gamescreen scene appears immediately (with no transition), and then the new gamescreen transitions over the old gamescreen.

Has anyone else seen this behavior?

While I’m here, to get kindle fire-resolution graphics to work, I added this line to config.lua:
["@1_875x"] = 1.874999,
1.875 does not work, even though 600 (kindle fire width in pixels) / 320 = 1.875. [import]uid: 94304 topic_id: 22873 reply_id: 322873[/import]