When installing CIS on a clean ThinkPad T30 (1.8 GHz Pentium 4 Mobile with 1 GB RAM), and trying to do the install scan, it downloaded the updates and then seemed to hang when installing them with the progress bar all the way to the right and no obvious disk activity. Twice I waited for 15 minutes before giving up and killing it. The Cancel button would not work, so I had to shut the system down. On the 3rd try I decided to wait a full 30 minutes, and the scan finally took off (followed by a normal install).
I consider this a pretty serious problem, both the long hang and the inoperable Cancel button.
Thanks for CIS and for listening,