Some search keywords in the omnibox have stopped working

Question

My problem in the same as described in the Google product forums with Chrome 21.0.1180.89.

When I type a search in the Chrome omnibox, after typing enfrSpace Chrome replaces it by a search in the history and I end up googling my search prefixed by the keyword.

Example: I end up googling enfr former, instead of translating former from English into French.

In my case, the search is the following in the Other search engines options:

• name: enfr
• keywoard: enfr
• search: http://translate.google.fr/#en/fr/%s

How do I restore the normal behavior (searching on the specified search engine instead of the default search)?

I have seen that clearing browsing data while I did the search fixes the problem. But I am not sure if it won't reappear.