I've used the Opera browser for several years & Adobe (Reader) 8 too, but after encountering some problems with 8, I uninstalled it & replaced it with the newest version of 10. While I've gotten nearly all the settings the way I want them, if I click on a link to a .pdf document using Opera, I'll always get this message: "No registered application for this extension." Using version 8, I did not have that problem & .pdf documents would open right away. They will open in IE, but I don't like IE & it's much slower than Opera.
I've gone thru every setting there is, Adobe Reader IS shown as an active plug-in for Opera & I also have extensions which should open .pdf files using Google Docs, but I will get that same error message every single time. I can right-click the link & save to Desktop (or anywhere else), but that involves additional steps I shouldn't need to take & didn't have to until I installed version 10. Should I just go back to 8, or try 9 ?? Almost forgot to list: Windose XP Pro, SP2, always-on (cable) business internet connection.