Problem with image width in views/ block
You can try hook_preprocess_image in template.php

function &lt;THEMENAME&gt;_preprocess_image(&amp;$variables) {
    // If this image is of the type 'thumbnail' then assign additional classes to it:
    if ($variables['style_name'] == 'thumbnail') {
        $variables['attributes']['class'][] = 'myclass';
        $variables['attributes']['class'][] = 'yourclass';
        $variables['attributes']['width'] = 'yourclass';
    }
}


OR 

function &lt;THEMENAME&gt;_image_style($variables) {
  $style_name = $variables['style_name'];
  //print_r($variables);
  $path = $variables['path'];
  $style_path = image_style_path($style_name, $path);
  if (!file_exists($style_path)) {
    $style_path = image_style_url($style_name, $path);
  }
  $variables['path'] = $style_path;
  if (is_file($style_path)) {
    if (list($width, $height, $type, $attributes) = @getimagesize($style_path)) {
      $variables['attributes'] = array('class' =&gt; 'fullwidth');     
      $variables['width'] = '400px';
      $variables['height'] = '400px';
    }
  }
  return theme('image', $variables);
}