Re: horizontal top bar
No, it doesn't depend on the theme. The level of functionality in question here is lower than themes, which only control appearance. (The CSS used to hide/display the menu dropdowns is in the css/cssmenus.css file, which is used by all themes.)
What Tiki version are you using? Minifying Javascript had some problems in Tiki 4, if I recall the release correctly, but works OK in Tiki 5.
I use Opera as my main browser but when there are display quirks compared to other browsers, there is some consolation in knowing it has a market share of only a few percent - in other words, not many site users will be affected. In any case, the combination of not minifying JS and minifying CSS should prevent the menu display problems in Opera, as far as I know (though, as mentioned, JS can be minified also in Tiki 5 and not cause problems for Opera). If pages are showing mixed results, it could be that some are being retrieved from cache; try clearing Tiki's caches (at tiki-admin_system.php). This is especially necessary when minifying is turned on. Another thing to keep in mind is that javascript is loaded last, after page content including the menus, which is why the menus don't display or work completely until everything is loaded.
-- Gary
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