Erase Flash cookie is cool and handy. But could become a nightmare
Because you can't select what cookie you want keep or delete.
And because, by default, you erase the most important cookie, setted by the player himself. The "main" cookie who remember the setting you want for your flash movies.
You could see the display manager here :
This manager show you, your settings. You can add security settings, by adding sites. You can choose default settings for each flash cookies ( size , ... )
Each time you select remove cookies, you erase this one. So you loose lot of work and information.
This is very important that you don't erase this cookie :
C:\Documents and Settings\[name]\Application Data\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\settings.sol
and this one too :
C:\Documents and Settings\[name]\Application Data\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\#local\settings.sol
This is so important, that I think you must keep them by default. Only erase these 2 cookie if the user really know and want to do this!