Index: ApiQueryGlobalUsage.php
===================================================================
--- ApiQueryGlobalUsage.php	(revision 69060)
+++ ApiQueryGlobalUsage.php	(working copy)
@@ -46,6 +46,7 @@
 			}
 			$query->setLimit( $params['limit'] );
 			$query->filterLocal( $params['filterlocal'] );
+			$query->ignoreCaseFirstChar();
 
 			# Execute the query
 			$query->execute();
Index: GlobalUsageImagePageHooks.php
===================================================================
--- GlobalUsageImagePageHooks.php	(revision 69060)
+++ GlobalUsageImagePageHooks.php	(working copy)
@@ -14,6 +14,7 @@
 		if ( !isset( self::$queryCache[$name] ) ) {
 			$query = new GlobalUsageQuery( $title );
 			$query->filterLocal();
+			$query->ignoreCaseFirstChar();
 			$query->execute();
 			
 			self::$queryCache[$name] = $query;
Index: GlobalUsageQuery.php
===================================================================
--- GlobalUsageQuery.php	(revision 69060)
+++ GlobalUsageQuery.php	(working copy)
@@ -11,6 +11,7 @@
 	private $result;
 	private $continue;
 	private $reversed = false;
+	private $target = null;
 
 	/**
 	 * @param $target mixed Title or db key, or array of db keys of target(s)
@@ -235,4 +236,49 @@
 	public function count() {
 		return count( $this->result );
 	}
+	
+	/**
+	 * Query both the lcfirst and ucfirst versions of the target. 
+	 * 
+	 * This may be necessary due to different capitalization settings between 
+	 * local and foreign wikis. If the foreign wiki is capitalized, both the 
+	 * lcfirst and ucfirst version of the filename will refer to the same file,
+	 * so we need to query both.
+	 */
+	public function ignoreCaseFirstChar() {	
+		$switchedTarget = array();
+		foreach ( (array)$this->target as $target ) {
+			$file = wfFindFile( $target );
+			if ( $file && !$file->getRepo()->initialCapital ) {
+				# Repo is uncapitalized
+				continue;
+			}
+			
+			$switched = self::switchCaseFirstChar( $target );
+			if ( $switched !== false ) {
+				$switchedTarget[] = $switched;
+			}
+		}
+		$this->target = array_merge( $this->target, $switched );
+	}
+	
+	/**
+	 * Return the db key with case switched first char.
+	 * 
+	 * @param $dbKey string Db key to switch
+	 * @return mixed Switched db key or false if unswitchable
+	 */
+	protected static function switchCaseFirstChar( $dbKey ) {
+		global $wgContLang;
+		$lcfirst = $wgContLang->lcfirst( $dbKey );
+		if ( $lcfirst !== $dbKey ) {
+			return $lcfirst;
+		}
+		$ucfirst = $wgContLang->ucfirst( $dbKey ); 
+		if ( $ucfirst !== $dbKey ) {
+			return $ucfirst;
+		}
+		return false;
+	}
+
 }
Index: SpecialGlobalUsage.php
===================================================================
--- SpecialGlobalUsage.php	(revision 69060)
+++ SpecialGlobalUsage.php	(working copy)
@@ -94,6 +94,7 @@
 			$query->setOffset( $wgRequest->getText( 'to' ), true );
 		$query->setLimit( $wgRequest->getInt( 'limit', 50 ) );
 		$query->filterLocal( $this->filterLocal );
+		$query->ignoreCaseFirstChar();
 
 		// Perform query
 		$query->execute();