I'm using Opera as my web-browser and it's perfectly good for me. What I like in it is that Opera uses its cache in pretty effective way, say it won't reload page when you click Back button, it just shows you the one from its cache. The second example it when you follow the link that was visited by you a minute ago it won't reload it as well.
And here we can face the problem. Say you go to your Friends page, then click on Latest entries of yourself, and after a while clicked "Friends" link again - what you may expect to see? Well, there should be renewed version of Friends page, but you're still see the one, cached one!
This is the problem of wrong cache management as the result of misunderstandings between Opera and the LJ site. Maybe it is could be fixed in the page's headers, maybe in it's meta tags, I haven't checked that, but the easiest way to fix it is to add "?" by the end of these links:
etc. This makes browser to treat these pages as a result of some dynamic page output (well, technically as the page produced by GET-type query) so it will threat the cached version pretty well: it will use it for a short time and after that time will use the page from the server. I think it worth the time spent on changing the template code :)