Install the plugin into either Galileo or Helios package.
To install it onto other version
for ex: if you have installed on Galileo, navigate to dropins folder under eclipse Galileo
copy the link file com.adobe.flexbuilder.feature.core.nl1 to the dropins folder of Helios.
That's it, now the Adobe Flex builder plugin will work for Eclipse Galileo and Helios.
-Shankar
To install it onto other version
for ex: if you have installed on Galileo, navigate to dropins folder under eclipse Galileo
copy the link file com.adobe.flexbuilder.feature.core.nl1 to the dropins folder of Helios.
That's it, now the Adobe Flex builder plugin will work for Eclipse Galileo and Helios.
-Shankar