When trying to resolve a Bus Error problem with BCC on my Media Composer 2.8, I decided to remove and reinstall BCC. I found my 4.2.1 CD but not the 4.2.2 updtaer I'd downloaded and mislaid. Some Google searching led me to the following link:

ftp://ftp.media100.com/pub/software/BorisFX

You can find the 422 updater there (it was not visible on the Boris site, which would now like to charge $39 per technical query).

as an Avid fan of boards (hahahaha) try posting your questions on the Creative Cow Boris forum, where the Boris guys offer their 'unofficial' but VERY helpful advise.  That's how I got my 4.2.2. to rock.