Rated 4 out of 5 stars

I got it. The problem that I can't change the search engine is caused by the conflict between this addon and "Organize Search Engines". Please consider fixing it.

This review is for a previous version of the add-on (0.7.17.20130121). 

Nice extension but there's something more to improve Rated 3 out of 5 stars

It's useful. But sometimes I change the default search engine by mistake, but it's not easy to change it back. I click on the name of search engine and wonna to change it, but nothing happens. Hope that to be fixed.
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Yes, I've click the pop-up name in the URL bar and select a new search engine, but nothing happens. I'm using firefox 18 beta6 on Win7 x64 sp1.

This review is for a previous version of the add-on (0.7.16.20121026). 

It should be as easy as it was to change the search engine. Normally, a pop-up is shown to change your search engine when click the search engine icon/name in the URL bar. What Firefox version are you using?