The subject problem occurs if the separator page file does NOT have the archive bit set.

To workaround this behavior, set the archive bit on the separator file:

1. Open a CMD.EXE window.

2. type the following command and press Enter:

attrib +a FileName

Where FileName is the fully qualified name of the separator page file, normally at %SystemRoot%\System32.

3. Add the separator page in the Printer Properties dialog.