I notice that context menu for PDF file is different between Explorer and Opus. In Explorer I see "Ouvrir dans Abode Reader 8" and "Imprimer", in Opus... nothing 
I try in a new fresh install, but items aren't display...
I try in other computer, it's ok but with adobe reader 6... 
I think this is a known issue and something unusual (not wrong but unusual) about the way Adobe Reader adds those context menu items.
I'm not sure whether or not it has been reported to GPSoftware but it's been mentioned before at least.
I remember taking a look at it and not being able to work out why, from the registry settings, the menu items don't appear in Opus.
You send a bug report (more easier for you to explain in good english words) ?