This is one year after the above post, dated Dec 2011. I am a satisifed user of Carbonite since this last summer - summer of 2012. I don't know for sure what the situation was in the time frame you were talking about, but I want to assure folks who read your post that your statement about not being able to restore individual files or folders is certainly not true now. In fact, they even have a mobile app now for accessing individual files with an iPad or iPhone:
This is a portion of Carbonite's help file on downloading individual files.
"About Your Restore Options
With Carbonite you can restore files individually one of two ways. One method is to restore files through the Carbonite Backup Drive. This is useful if you know where the file(s) are located and are more interested in navigating to them like you normally do on your computer. The other method for restoring individual files and folders is to use the Restore Search. This method is useful to people who are unsure of a file's name or location and wish to search their backup for the file."