It needs to be clarified that, differently from Version 9, the Preview in Version 10 simulates an internet connection. This means that the video is streamed from a web server. This can cause some delays on the streaming, like it happens once online.

This issue can be caused by several reasons, depending on the file type used.

• .mp4, .wmv, .flv, .mov: Normally these file types support the streaming which means that the movie is played while it is downloaded. To make the streaming work correctly it is important that the headers (the fields that indicate the length and size) are placed at the begin of the file. Not all files have these placed correctly. In most video converted programs there is an option called, as example "enable streaming" which adds the fields correctly in the header. Once done these video files will support the streaming features.

• .avi, .mpg: These files don't support the streaming feature and they need first to be completely downloaded to be played. This can take several time according to the size of the file. For this reason, we don't recommend the use of files in these formats in the size exceeds 10MB