Arrowhed, When you drilled the hole in the alternator bracket did you use a drill press?
If you drilled with a hand drill the hole may not be perpendicular to the bracket causing the belt to not track properly.
Check this YouTube video, showing the correct belt installation.
The belt was installed on an engine with out a front clip for clarity.
http://www.youtube.com/watch?v=sBGAPMId4Ds
Also on you tube use the search words "Serpentine belt alignment.
Here's another good video.
Ensure the belt ribs are alinged in the groves.
http://www.youtube.com/watch?v=sBGAPMId4Ds