I tried it on my girlfriends S2; we followed the directions precisely but we got some odd error messages about the device not being found, and the phone stopped

I tried it on my girlfriends S2; we followed the directions precisely but we got some odd error messages about the device not being found, and the phone stopped being able to boot. Had to go through a "normal" Cyanogen installation procedure to get it working again; not hard for me but nothing you want a non-technical person going through (hence why the installer exists). I have no idea what the percentage of people having problems is, but it certainly happened to more than one person...