There seems to be a problem with the iPhone mp4 videos not playing on iPhones. This is a new problem as they all worked ok when first ‘upped’. It doesn’t seem to be a bandwidth limitation issue from the server; the files are still all there; they all played/streamed ok for a long time. I’m looking in to it and will correct as soon as I find the solution.

my bad. I had turned off plug-in support on my iPhone in order to try and stop Safari crashing so much …with the result that QuickTime video support got turned off as well… : – )
Solution = Settings: Safari: Plug-Ins: ON