None of them will allow you to open a CS4 or later .indd file.
You should be able to open a .inx file exported from CS4 in 5.0.4
Are you trying to open a CS3 file in CS4 or a CS4 file in CS3?
Attempting to open a CS4 file in CS3.
Then follow Peter’s instructions.
My script in this thread: http://forums.adobe.com/message/4071273 will identify with what version of ID a file is created, which may be helpful at times. (Aside, you may be the first to try it with CS3 -- so it might not work.)
Nothing to be ashamed of on your side, really. That infernally misleading "upgrade your plugins" 'error' dialog has been confusing first-time users from the very first time some lazy programmer at Adobe opted for a quick shortcut in programming and be at home before rush hour.