....aaahh the PDF-XChange PDF Preview Provider (not "XP") also works (and doesn't steal focus)!
Unfortunately however, it doesn't seem to support anything else than continuous page view, also no page thumbnails and no search. What's more, it ALSO is slower (when scrolling) than the ActiveX preview version of PDF-XChange Viewer 
Bummer! Dopus as crashed (with the PDF-XChange PDF Preview Provider active), and now if re-started just sits in the tray and does nothing (no tray menu, no lister) 
Any ideas how this can be fixed? Hack the Registry in order to disable the PDF-XChange PDF Preview Provider?
Thanks already
Cheers David.P
Opus will only use it if it's configured to in the ActiveX plugin (i.e. the screenshot you showed before).
If you're trying different PDF viewers, make sure you move the .pdf extension to them as well as enabling them. (If the viewer is enabled -- i.e. ticked -- but doesn't have the extension, it won't be tried. If it isn't enabled it won't be tried either, of course.)