It also depends upon the scan settings you are using. Try running a scan using default settings.
If a user scans everything one could get these messages. For most newbies default settings are fine.
If a user so desires they can create a "report" shortcut on their desk top.
Here are some step by step instructions
http://www.youtube.com/watch?v=ntW8zGicUfkBe sure you have "generate report" enabled in your settings.
Personally this has been very handy to use. It will show why a specific file cannot be scanned including the file path.