Comment 6 for bug 936920

I can confirm this is still happening. For me only the default search engines are affected, meaning google.com, duckduckgo.com, ebay.com, amazon.com, twitter.com, wikipedia (english) and yahoo.com.
The must get readded as they also are listed on bottom in the list of search engines after every update AND more importantly are readded although I usually delete most of them anyway.