Problem with PDF Writer after UA install

[<SparTacuS>]

I know this is not strictly 100% unattended but my problem only occurs on those machines installed in this way.

When installing Adobe Acrobat (V5 or 6) the PDF Writer Component will not install.

This is the component that appears as a "virtual" printer to create PDF docs. In v5 it doesn't even throw an error - it just never installs, in v6 it gives an error saying that this module may not be availible.

I believe that the fault lies with something that I've either removed, disabled or switched off. But I've made seemingly endlees changes and don't know where to start.

Other "real" printers install OK, and the Spooler service is running.

Anyone give me a clue where to start?

PS - Acrobat is not being installed as part of the UA but using the normal CD afterwards.