Hello
I am Rich1108.
I have the same problem you have with a large 52 min video on my ipad that all of the PC file managers do not see, even though they see all of the other videos on my ipad. I have tried importing etc., and I always just get everything except the large file in question. I have a 13 GB (16-used elsewhere?) ipad, and I believe that the 52 min movie takes all but 700 MB of my 13 GB.
An associate at the Apple store near me told me to try Kodac EasyShare instead of the windows applications, but I don't think that is a good answer. I have not tried it because one of my old computers uses a Kodac application to offload pictures from an old camera, and that is not a good application. (It works, but is slow and does not really provide me with anything I can't do better with Windows Explorer. And I don't like the way it works).
But that is my only option right now. I got a reply from Texas Mac Man, but he only referred me to standard methods. He does not seem to understand that this large video defies the usual methods. I did find a place where it was stated that the Import feature can only get files up to 500 Megabytes. I have reason to believe that my video is about 12 GB.
By the way, you probably have found that you also cannot trim your large video. It seems that the ipad looks at the size and balks at that. Mine says it can't trim because the file is too big. That is before it even asks me if I want to trim the original or create a new sub-video. But you might try trimming your video into smaller parts if your ipad will let you do that. I think the import problem definitely has something to do with the size of the video. You could always put the video back together again with a decent movie application. (I use the one that comes free with Windows 7 called Microsoft Movie Maker or somehting like that.) But unfortunately most of my valuable ipad movies were taken so that they show up upsidedown on most viewing applications, except the ipad. There is probably an application that will fix that, but I have not found it yet.
Please let me know if you find a solution to this large video problem. I need to free up space on my ipad if nothing else, so I can't wait too long to delete this 52 min thing from the ipad.
Thanks
Rich1108