retain Layers when converting to PDF

[qball]

I recently discovered that PDF files have a Layers tab that can control whether layers are visible or not, like Autocad. So how do I retain those layers when converting from Autocad to PDF? All my pdf's don't have any Layers options.
I'm using PDF X-Change 3.0 and Autocad 2007.

[fuccaro]

In the past I used the full Acrobat program to plot drawings in PDF format and it retained all the layers.
I think it is up to the converter.

[kari_sinkko]

There's also PDF Creator which is free for non commercial use. As for printing pdf's in 2007, You can use DWG to PDF.pc3 plotter.

To configure the PDF driver, in the Add-a-Plotter wizard, select Autodesk ePlot (PDF) from the Manufacturers list, and select PDF from the Models list. (REF:2007 Help file)