Serpentine belt wear problems

I just noticed that the serpentine belt on my rodeo (3.2L) is running off
the harmonic balancer and alternator pulleys. I put a new belt on and
then the belt started running off the back of the fan pulley. Then I
noticed that the back of the fan pulley is not in line with the rest of the
pulleys. It is about 1/2 inch forward compared to the rest. I'm sure that
this is what is causing my problems. I think that sometime in the past the
fan hub must have gone bad, then whoever replaced the part either didn't
notice the difference, or they got it from an older 3.2L in a salvage yard.

So I guess these are my questions:
What is the stock depth of pulley that is supposed to be on a 99 3.2L?
Are the fan hubs different lengths throughout the years?
Has anyone had this problem with a Isuzu rodeo before?

Vehicle is a 99 Isuzu rodeo/w 3.2L 4x4

thanks for any advice

There is another thread on the first page of this board about the balancer going bad and causing this issue.

http://http://picture.vzw.com:80/mi/251615826_846871431_0.jpeg?limitsize=345,345&outquality=56&ext=.jpg&border=2,0,0,0

Well I think I figured out what the problem is LOL. I've got a fan bracket in the mail should be here tomorrow. Thanks for the help.

Guess that isn't didn't work. I'll try again

http://viewmorepics.myspace.com/index.cfm?fuseaction=user.editAlbumPhoto&albumID=1422103&imageID=19097821&MyToken=5d2462e1-f695-43bc-80cf-50bb4deedb2b

The part that holds the pulley and fan moved off the shaft, and you can't tell by the picture, but it is crooked. That is probably why it broke the bracket. I put the new one on from utahparts.com, and I have no more belt issues