Expression Studio encoded my video in (.wmv) file format, so converting the video using Format Factory in (.mp4) is causing some problems, this length remains same if played on windows media player or VLC, but uploading on YouTube is doubling its length.
So if I encoded my video (.wmv) format and uploaded directly to YouTube, everything works fine, but converting it to (.mp4) and then uploading to YouTube is doubling the video length.
Conclusion : Problem is with Format Factory converting.
Solution : Upgrade to the latest version of Format Factory (with version 3.5 problem was resolved after testing same files)
Cheers