Those of you Opera users that have problems with accents in the address and search bars (for example, I couldn't type έ or ά in Greek), in case you have compositing enabled, disable it and restart Opera. Otherwise you can start Opera like this:
and the problems will go away. This has been an annoying problem for me (I don't remember which version introduced this issue, maybe 10.60) and I was looking forward for a solution. This simply does it.