There are only 4 known sources for dropped frames. They re not specific to this player.
1 - Bugs in the Flash Player (please ensure latest version)
2 - Processor over loaded - cannot decode in time.
3 - Out of Memory to decode in a timely manner (try a system restart)
4 - Out of Bandwidth - (encode the H264 at a lower quality)
http://www.aspnetmedia.com