Thanks to the help from wasted, the issue of "Quick Edit" icons mentioned was solved finally.
wasted has summarized the problem nicely and concisely that both of the followings have to be enabled for these icons to work (i.e. to load the authorization.css successfully):
- 3rd-party cookies
- HTTP Referer
Actually I did confirmed the 3rd-party cookies blocking was disabled in Firefox when I tested it before, while in IE the relevant settings are left default: "Override automatic cookie handling" is off. That's why I thought the problem wasn't there.
That means, referrer has to be the cause. I have to admit that I really missed this during my test, but according to my poor memory I didn't set anything relevant explicitly. And as what wasted say, since Opera is working on the same machine, those security software should not be related in this case (some of them removed the referrer in the header to protect privacy). To play safe, I double checked the option in my WebDeveloper Toolbar Firefox extension, oops... the "Disable Referrers" option is on! I don't know when it is turned on, but anyway, turning it off make the long-missed icons appear again! For those Firefox users who didn't install this extension may try to modify the configuration yourself. Steps are here:
- Type about:config in your Firefox location bar, and press Enter.
(For Firefox 3 users, you may be prompted the following warning. No worry, just press "I'll be care, I promise!" is fine. Funny warning, ha...)
- Type "Referer" (single-R) in the filter bar, and you will then see a preference value named network.http.sendRefererHeader, set its value to 2. If the preference value does not exist, create one of integer type and set to 2.
- Reload your blog, and you will see those icons if you are logged in.
- You don't need to restart Firefox to reload this setting. But if there is no effect after changing the value, try to restart your Firefox.
So the problem only remains in IE now. Although I don't use IE frequently, my curiosity doesn't allow me to ignore the problem. I don't remember installing any plugins to IE or changing any relevant settings blocking HTTP referrer, and most importantly I can see the Referer header from IE while I was inspecting the network packets last time. If HTTP Referer is not the cause, 3rd-party cookies has to be. This implies the so called "automatic cookie handling" in IE7, unlike previous versions of IE, has blocked 3rd-party cookies somehow. This is actually a good move in terms of user's privacy but I have to say the interface is somehow misleading.

As you can see from the above screenshot, when the "Override automatic cookie handling" option is disabled, the radio box next to "Allow Third-party cookies" is filled. This gives users (at least me) a wrong implication that "automatic cookie handling" allows 3rd-party cookies by default...
Anyway, by overriding the behavior to allow 3rd-party cookies, and the icons are really out again. So all issues are solved now. Hurray!
A final note to add is that you can (and should) use an alternative way to allow the required cookies in IE7 without compromising your privacy. Instead of allowing 3rd-party cookies globally, add blogger.com to the whitelist. To do so:
- Go to the Privacy tab in your Internet Options. Click the Sites button.
- Type "blogger.com" in the Address of website field and then press the Allow button. Press OK twice to save the settings.
- Reload your blog. You will see those icons again if you have logged in.
Wish this article could help others who encounter simiar problems. Happy blogging!

