I downloaded a 7MB 8sec sample clip from http://blog.rfquerin.org/2009/04/12/the-kodak-zi6-sample-videos-and-thoughts/
( http://rfquerin.org/Zi6Samples/Zi6_MacroSample.MOV )
and it plays OK in VLC player, Media Player Classic, QuickTime 7.6 but not Windows Media Player. And, like you, I can't get it to load in VideoPad either! While it appeared to convert in Prism the resulting file was too small and won't play. And it crashes VirtualDub. MPEG Streamclip plays it.
MediaInfo says:
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 8s 541ms
Bit rate mode : Variable
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 fps
Stream size : 6.93 MiB (96%)
Title : Ambarella AVC / Ambarella AVC
VideoGSpot says it's 'avc1 ' 'H.264 ' and pressing the test button it won't play (MP4 Splitter --> ffdShow).
First time I've had trouble with anything H.264 
In the absence of a codec for the Ambarella flavour of AVC that could Make It So with VideoPad, you'll be stuck with converting to another format first.