Trying to help with some outside testing...
It didn't work on my 3GS either, but ran fine in my desktop browsers and on my Galaxy Tab with Android 2.2 under a few different browsers (Opera, Dolphin, etc.) I went ahead and tried it out on my iPad, too, and it didn't work either, so my guess is it's something iOS-related.
Unfortunately I haven't been using Construct 2 long enough to be of much help in troubleshooting and there are others on here that know WAY more than I do, so hopefully my testing gives someone some ideas and they can chime in.
If there's anything else I can possibly help with let me know. I'm willing to try.