Rhythmbox Music player - password window popping issue!

I have been using Rhythmbox music player since almost 3 years now. Suddenly one day, it started popping a Give_ur_password type of window at every track. I used to close the box, then it would pop up again for thrice or so. It looked like the following.

I tried Google-ing of course, but could not find anything. There were some posts regarding why / how some plug-ins for Rhythmbox keep popping windows. I did not find anything related to password window specifically. Still, I opened Edit->Plug-ins and observed that few plug-ins were enabled. For no apparent reason, I disabled the plug-in for Cover art (as shown below) and never got those disturbing pop up windows again!

What I don't understand though is, that plug in was always enabled afaik, because I never explicitly enabled / disabled it in past, then why suddenly after almost 2.5 years, it started popping up windows?! Another thing is, as shown in first image, there is something called "xml.amazon-proxy caching server" - Have no clue how it could be related to cover art of an album!

Anyways, will definitely post the explanation if I can find one, for time being let me enjoy the pop-up_window_free Rhythmbox!

carbon trading

I had heard this term.. of course without knowing the meaning.. During "Applied Economics" (!!) lecture, Sir explained it.. As follows:

Lets assume for a certain area, air pollution restrictions are laid.. in a sense.. no factory should emit (say) 100 units of carbon (carbon- in a sense, pollution causing element). Lets say in that area, there are 2 companies A and B.. A's factory is controlling its emission to say 80 units of carbon.. Then they are given a sort of "carbon saver" certificate, indication of "they are carbon savers" That certificate is considered of having a value. Because, if suppose company B's factory is not able to control their emission to 100, say they emit 120 amount of carbon.. they can acquire (may be, actually BUY) this "carbon saver" certificate from company A!! sort of license.. to emit higher amount of carbon.. So that total level of carbon in that area is kept constant (120 + 80) as well as because company A has saved carbon, they are given reward while company B which could not save carbon, is - in a sense - penalized.

Cool information.. isn't it?