There are 2 possible reasons:

• The first is that you are running in document scanning mode rather than batch scanning mode. If none of the scanned pages are displayed with either a red or yellow border then you are definately in document scanning mode. You need to tick the 'Use Batch Scanning' option on the Profiling tab of the Operator Actions form (F1).
• Secondly you may have set the '% White Space For Separator' to the wrong value. A value of less than 50% (normally 10%) suggests you are using black separator pages, whilst a value of greater than 50% (normally 99.5%) suggests you are using white separator pages.