Copying libflashplayer.so version 9.0.48 over /usr/lib/flashplugin-nonfree/libflashplayer.so 9.0.115 solves the issue.
I think this should be a problem of synchronization between nspluginwrapper and libflshplayer.so.
Now I can definitively confirm that support of Adobe Flash plugin it's broken in Gutsy 64.
Copying libflashplayer.so version 9.0.48 over /usr/lib/ flashplugin- nonfree/ libflashplayer. so 9.0.115 solves the issue.
I think this should be a problem of synchronization between nspluginwrapper and libflshplayer.so.
Now I can definitively confirm that support of Adobe Flash plugin it's broken in Gutsy 64.