this is just calling for jokes.
i dont use Opera much, but i had similar trouble when upgrading some versions of Firefox... like trying Deer Park, i would install on other partition and start it.... process would start in TM, but thats it, it wouldnt load at all.... it also requiered to delete profile from other FF instalation and that was big NO-NO cause i have too many exstensions to lose whole day trying to install them all again....
i know that FF issue is that it stores profile data in "documents and setting/user/blah...blah..." instead in folder where you installed the damned program.... maybe its something like with Opera also?