For people having problems with Opera Mobile only opening mobile versions of pages I suggest you try this. Creating a custom user-agent to trick the websites into thinking you're using a desktop device.
1) In the browser enter "Opera:Config" with out the " 's to load the Preferences Editor
2) Select User Agent and change the value to 3 and press save.
3) Select User Pref, scroll down and find Custom User-Agent and type this exactly.
Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
4) Scroll down further and press save.
5) Exit Opera Mobile and restart your device.
It's important that you format that sentence correctly to trick pages into loading the desktop versions of their site. Don't leave out the proper spacing. Also note, this doesn't work with Opera Turbo engaged but under normals browsing usage you'll no longer recieve mobile pages unless you type them in directly i.e.
http://m.youtube.com
This method works for both 8.5 and the just released 8.7.
Let me know if this helps and you're welcome.