You must have GNU Recode 3.5 or higher installed on your system. You can download the package from » http://directory.fsf.org/All_GNU_Packages/recode.html.
The Recode library version 3.6 adds weird characters behind converted strings under certain circumstances. Thus it's safer to use Recode v3.5 or one of the available alternatives like the iconv or mbstring extension.
