Every since I've got my new Thinkpad X61 with Windows Vista (Business 32-bit), the ThinkVantage Access Connections (AC) application has been freezing frequently. The Access Connections is used supposed to be a utility to make it easier to connect to different wireless and LAN networks, but all this freezing has been rather frustrating.
I finally decided to track down the problem and found out that the problem with AC has been reported by many (Thinkpads.com, FlyerTalk, m3rLinEz, ...). It seems that it occurred on both XP and Vista and various types of Thinkpads.
Solution: Download and install the new AC 5.12 for Windows Vista (released 2009-01-13) from Lenovo website. Make sure to read the installation notes, saying that the Lenovo System Interface Driver, ThinkPad Power Management Driver, and the Hotkey Driver must be up to date before updating the AC (I had to install two of these). Note also that the files downloaded will only extract the setup files - you then have to launch these manually.
I used to have AC 4.42 for Windows Vista (Build 7RCN38WW). After installing AC 5.12 (on January 15, 2009) for Windows Vista (Build 7VCV85WW), I haven't experienced any problem.