Bug in Settings: Manage search engines...
In the Search-Settings: Set which search engine is used when searching from the omnibox
Adding a searchengine will not be listet in the box/pull-down-menu for setting a new default one. Only bing, yahoo and google are on the list
my system: win7 home premium 64bit on C installed, Comodo for Chrome v31 on E (other partition on same HD)
several extensions: FlashControl, ScriptBlock, Ghostery, PrivDog, KB SSL Enforcer, TrafficLight, Zenmate, TooManyTabs for Chrome, Comodo Web Inspector (all for incognito mode activated)