Why is the thumbnail option greyed out in CS2?

I am using Windows XP. In windows explorer, I can see a thumbnail of my photoshop files saved as TIFFS and saved as PDFs but not saved as Psds. The Psds appear as black squares in windows explorer. In "filmstrip" view - I get a message "no preview available" for the Psds. Again the PDFs and the TIFFS are viewable in filmstrip view.

The save dialoge box has the word "thumbnail" greyed out. Sometimes it is automatically checked, and sometimes not depending on the format, but I do not seem to have the option of manual checking it. I want to save in Psds and see previews and thumbnails in Windows Explorer -- but the word "thumbnail" is always greyed out.

Thanks,
Selwyn

The ability to view PSD thumnails in Windows Explorer was removed after PS7 due to a problem with Windows XP which was causing some users to lose files.

Use Bridge.

Thanks Chris and Michael.

Selwyn