Maybe the one offered by lastpass for Opera is just a different extension compared to the one offered by addons.opera.com. Even if they're both offered by someone from lastpass, maybe the have different IDs or something. Haven't checked. The one on lastpass.com says it's 4.1.44, but the the filename that gets downloaded shows an older version. Not sure how they do things to know if that's the issue or not.
Without knowing what's up, I'd stick to using the Chrome version of the extension. I heard it gets updated the most anyway.