Well, just figured it out and maybe it's not correct.
The tab is based on the live version from XFM studios.

Tuning I used is: C#-G#-C#-G#-C#-C#


I Am Weightless
:Septembre:
Rule 3: Conceal Your Intentions
Website: www.myspace.com/septembre

Intro (just play the chord over and over)

C#|-------------------------|
C#|-------------------------|
G#|-------------------------|
C#|-7-7-7-7-7-7-7-7---------|
G#|-7-7-7-7-7-7-7-7---------|
C#|-7-7-7-7-7-7-7-7---------|


Verse 1 (You mean...)

C#|------------0-------------|
C#|------------0-------------|
G#|------------0-------------|
C#|-7--10-9--7-----3-4-------|
G#|-7--10-9--7-----3-4-------|
C#|-7--10-9--7-----3-4-------|


Verse 2 (If you only...)

Almost the same of Verse 1. However, guitar's almost inaudible in that part.


Chorus (I'll go alone...)

C#|-------------|
C#|-------------|
G#|-------------|
C#|-2--3--4-----|
G#|-0--3--4-----|
C#|----3--4-----|


Verse 1 (what do...) (play that the first time, then the verse 1 is the same of above)

C#|------------------------|
C#|------------------------|
G#|------------------------|
C#|--7~-----7---3-4--------|
G#|--7~-----7---3-4--------|
C#|--7~-----7---3-4--------|


Then Verse 2, Chorus, etc...

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As you can see, I'm not writing the whole song and the times you have to play each 
because it's easy to figure out.
But my ear is not perfect, so I'm missing some things.

One of them is what Terry plays in the chorus, after playing the F#. I think it's a 
on/off thing or something like that.

Then, I can't see what he's playing at the end of the song (the part 'Easily...'), I 
keep trying.

And as I said before, this is the live version played at XFM Studios. If you want to 
along the studio version, just play it in Drop D or Standard tuning.

It's not perfect, but I hope it helps! I'd like to see some Septembre stuff in Ultimate-Guitar.

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And don't forget to check out the new Terry's solo project, FEARS.
It's amazing, go to that myspace if you liked Septembre... you won't regret it:

www.myspace.com/iamfears