tilecache: no module named image

got

An error occurred: No module named Image
  File "/usr/local/apache2/htdocs/tilecache/TileCache/Service.py", line 323, in cgiHandler
    format, image = service.dispatchRequest( params, path_info, req_method, host )
  File "/usr/local/apache2/htdocs/tilecache/TileCache/Service.py", line 208, in dispatchRequest
    return self.renderTile(tile, params.has_key('FORCE'))
  File "/usr/local/apache2/htdocs/tilecache/TileCache/Service.py", line 138, in renderTile
    data = layer.render(tile, force=force)
  File "/usr/local/apache2/htdocs/tilecache/TileCache/Layer.py", line 435, in render
    image = self.renderMetaTile(metatile, tile)
  File "/usr/local/apache2/htdocs/tilecache/TileCache/Layer.py", line 393, in renderMetaTile
    import StringIO, Image
?

try removing metaTile from your tilecache.cfg