Because none of the others are quite right.

Worked out from his live DVD.

Feel free to leave input :)

Won't tab the strumming, as that's fairly easy to work out (and I'm lazy). Also, as it's 
Dallas, it's different every time he plays it, so I won't bother tabbing any of the 
extra little bits he throws in.

Drop D
Capo 4th Fret.

h - hammer on
p - pull off
/ - Slide
~ - Let Ring
= - Strumming


INTRO
e|---------0-2-------2h3p2---2----------0=-------0=------0=------------|
B|-------------0-----0-----3---3--------0=-------2=------2=------------|
G|---------------0---0-----------0------0=-------0=------0=------------|
D|--0-h-2------------2-----------------/4=-------2=------4=------------|
A|-------------------------------------/5=-------3=------3=------------|
D|---------------------------------------------------------------------|

e|---------0-2-------2h3p2---2----------0-5=-----0=------0=------------|
B|-------------0-----0-----3---3--------0-0=-----2=------2=------------|
G|---------------0---0-----------0------0-0=-----0=------0=------------|
D|--0-h-2------------2-----------------/4-4=-----2=------4=------------|
A|-------------------------------------/5-5=-----3=------3=------------|
D|---------------------------------------------------------------------|


VERSE A
e|---0=----------0=-------------0=------0=-----------------------------|
B|---0=----------0=-------------2=------2=-----------------------------|
G|---0=----------2=-------------0=------0=-----------------------------|
D|---4=----------4=-------------2=------4=-----------------------------|
A|---2=----------0=-------------3=------3=-----------------------------|
D|---x-----------0=-------------x-------x------------------------------|

VERSE B
e|---0=-------------------------0=-------------------------------------|
B|---0=-------------------------2=-------------------------------------|
G|---2=-------------------------0=-------------------------------------|
D|---4=-------------------------2=-------------------------------------|
A|---0=-------------------------3=-------------------------------------|
D|---0=-------------------------x--------------------------------------|

Those 3 bits are repeated throughout the song, it's easy to figure out where.

I think this is right. Enjoy :)