this is how i play it and it sounds right. if it doesnt for you then your playing it wrong.

Riff 1
E----------------------------------------------|
B----------------------------------------------|
G----------------------------------------------|
D-9-7-9-9-9-9-9-7-9-9-9-----9-7-9-9-9-9-9-7-9--|   play this 2x
A-9-5-7-7-7-7-7-5-7-7-7-----9-5-7-7-7-7-7-5-7--|
E----------------------------------------------|

Riff 2
E---------------------------------------15----------|
B------------------------15----------------12-14-15-|
G--9-11-13v---13-14-16v----------12-13--------------|
D----------------------------12---------------------| play this while another
A---------------------------------------------------| guitar plays Riff 1
E---------------------------------------------------|

Then play Riff 1 again