Because of Opera's File I/O security, you'll need to explicitly allow access to the location of these files. On first run, LSOManager will enter setup:
On Ubuntu this location is
On Windows this location might look like
C:\Documents and Settings\your username\Application Data\Macromedia
After mounting the proper location and restarting LSOManager, you'll be presented with a screen similar to this:
Here you can search, sort, delete and mark certain flash cookies/settings protected from deletion.
You can try it out here: LSOManager.wgt