GeoHot fixed some minor things with his BlackRa1n Jailbreak application. Download BlackRa1nh here.

** Update — RC2 is out **
Fixed 3G issues
Tethered jailbreak for 3.1 OOTB ipt 8GB and new 3GSes
Fixed Icy issues
Both Windows and Mac
If you used RC1 with success, no need to rerun