Bizarre issue. Installed plugin; set the video tag in my file...and it was looking for the .swf file that loads the player in the wrong directory. I did nothing other than uploading the zip and placing the tag, so the plugin is creating the wrong directory.
I changed the plugin directory to flash-video-player-html5 (which is where the plugin was looking for the swf file), deactivated, reactivated and it worked.
-Erica
http://wordpress.org/extend/plugins/html5-and-flash-video-player/