curse the automatic flushing potties!

(Knock on wood) we're doing pretty well using the potty, but we have had some inssues when out in public. While Spencer initially thought it was great fun to use different potties, and he was intrigued with the ones that flush automatically, but a few too many flushed while he was still sitting on them. Now we've reached the point where he is absolutely terrified to use a potty in public when he doesn't see a handle for flushing. He litterally screams and cries and absolutely refuses to pee. Yesterday afternoon he held it for for two and a half hours until we returned home! While I was impressed at his ability to do that, this is not good.