Try again after rebooting with ctrl+alt+delete.
Did you get the latest/last Android flash version from the adobe archives page?
Make sure the plugin setting is not disabled entirely.
After a while,video based actions fail completely for some odd reason until I restart my device.
This problem makes all forms of YouTube,and all SWF and flash player related videos fail to work.
Get an swf player app and an swf file like Ultimate Sonic Flash to test it with if you wish.