I could be something with your skin.

Do the following test

Use your skin on a page, a see if the search text is localized, then change the skin on that page to the one from my sample.

Check again for localization of the search string

If your skins still have the problem and mine not, then you have problems with your skin

Yes, if changing the skin leaves you with the error then your problem is your skin.

I can help you to check your skin if you send it to locopon at tiendaboliviana dot com