For all of those having trouble with the flash plugin, follow these instructions exactly:
Get the flash-plugin RPM from here, or add the apt or yum sources to your package management tool configuration.
Read this announcement in order to test the newer flash-plugin package. Same plugin binary, but it installs a bit smoother for some users especially if you have MozillaFirebird from fedora.us or Dag's repository.
2) FC1 requires that you install compat-libstdc++ in order for the flash plugin to function. This is true of both installing the plugin manually or installing the flash-plugin package.
I found the compat-libstdc++ package in the Redhat 9 distribution and the FC1 development directory, but not in the FC1 release (or updates directory).