Smart HD switch is experimental option used when user switched between 2 videos of different quality.
It works only for Pseudo-HTTP and RTMP streaming.

When this is Pseudo-HTTP, streaming modules on certain webserver (lighttpd,nginx,etc) must be preperly installed and well configured. Proper video mimetypes must be set for FLV and MP4 videos.

Of course video file must be prepared for http-pseudo streaming. Keyframes must be set.
Before video skipped to certain time position, each player calculates new position based on keyframes information.
FLV videos are usually keyframed with tools like FLVTool2 or Yamdi. MP4 videos with MP4Box.

If you find smartHD switch not working properly, the problem is in your server or in your video.
There is hidden flashvar, so you can unset SmartHD feature. Then when video switched to alternative quality video, it will start playing from start position.

To switch off SmartHD support you can set flahvar: <smarthd>false</smarthd>
If you use php, the code is: print "<smarthd>false</smarthd>\n";
For scripts like Clipshare or AVS it can be used in player's config.php file.

Nuevolab Support.