http://www.cirp.org/library/disease/HIV/vanhowe4/
This article, while I have NOT read it all, seems to point in the exact opposite direction.
Furthermore, while by now means an authority albethey well researched, Penn & Teller did a Bullshit on circumcision of men, where this theory was taken apart. Unfortunately Showtime's website is open only to US computers, and I'm in scandinavia...
Personally I think its complete crap. There is no difference, medically, between cut and uncut, as long as proper hygiene(sp?) is observed.
My 2 cents...