I called the Asus tech support line and all I had to say was "My chipset fan..." and the guy interrupted me and said "Oh you have the Asus A8N-SLI Deluxe?" I replied "Yes" and he said they were "recalling" the original fans because they were defective. I asked if it was a genuine recall and he said no that it was just something they were told to be aware of. He forwarded me the e-mail that was sent to the CSRs... Here it is...
"There is a slight difference between the original chipset fan and new fan for the A8N SLI Dlx. Please see following attachment. Please make sure to notify customer of this if you will be sending them a replacement to avoid customer calling us about this simple issue.
Note that this is the improvised fan, that shouldn't be unstable like the original fan."
The e-mail included a pic of the old chipset fan and the new one. It looks like the new one attached at a 45 degree angle compared to the original. I will post the pic later tonight.
I asked if the new one was quieter and he replied, "Yes, very much so." I asked if I needed to RMA my board and he said "No, not unless your current board overheated due to the old chipset fan."
My replacement fan should be here next week.
EDIT:
Pic of old/new fan.