Couple of changes to WordPress 2.9 coming along – including deprecating streams.php and gettext.php in the includes.
There’s a ticket on it here – http://core.trac.wordpress.org/ticket/10890
The easy fix is to comment out the lines where the modules are loaded:
WeatherIcon.php55 # Fixes a bug in l10n.php where some guy decided there was no reason 56 # to load files which are required for their l10n functions if no 57 # language is defined in WordPress. 58 #require_once(ABSPATH . 'wp-includes/streams.php'); 59 #require_once(ABSPATH . 'wp-includes/gettext.php');