Here’s a blog post by a frustrated developer who seems to have found out how to set up the Flex Builder plugin with Eclipse 3.5 (I have tried it and it works!). Thank you, frustrated developer!
From the post:
(1) Download and install Eclipse 3.5. I used the J2EE install.
(2) Download and run the Flex Builder 3 installer.
(3) Ignore all the warnings that it only supports Eclipse 3.3 and 3.4. Just keep telling it that you know what you are doing and want to install it anyway. It will end with a scary message about failing and suggest you do a manual install from inside of eclipse. Don’t do that!
(4) Here is the magic, when it is done there will be a file in your eclipse/links directory called
Open that file in wordpad and you will see it contains one line:
C:/Program Files/Adobe/Flex Builder 3 Plug-in
Edit that line so it looks like this:
path=C:/Program Files/Adobe/Flex Builder 3 Plug-in
Save the file and start eclipse. Voilla!