diff --git modules/image/image.admin.inc modules/image/image.admin.inc
index 1f1121c..dafdb4b 100644
--- modules/image/image.admin.inc
+++ modules/image/image.admin.inc
@@ -774,49 +774,49 @@ function theme_image_style_preview($variables) {
 
   // Set up preview file information.
   $preview_file = image_style_path($style['name'], $original_path);
-  if (!file_exists($preview_file)) {
-    image_style_create_derivative($style, $original_path, $preview_file);
-  }
-  $preview_image = image_get_info($preview_file);
-  if ($preview_image['width'] > $preview_image['height']) {
-    $preview_width = min($preview_image['width'], $sample_width);
-    $preview_height = round($preview_width / $preview_image['width'] * $preview_image['height']);
-  }
-  else {
-    $preview_height = min($preview_image['height'], $sample_height);
-    $preview_width = round($preview_height / $preview_image['height'] * $preview_image['width']);
-  }
-  $preview_attributes = array_intersect_key($preview_image, array('width' => '', 'height' => ''));
-  $preview_attributes['style'] = 'width: ' . $preview_width . 'px; height: ' . $preview_height . 'px;';
-
-  // In the previews, timestamps are added to prevent caching of images.
-  $output = '<div class="image-style-preview preview clearfix">';
-
-  // Build the preview of the original image.
-  $original_url = file_create_url($original_path);
-  $output .= '<div class="preview-image-wrapper">';
-  $output .= t('original') . ' (' . l(t('view actual size'), $original_url) . ')';
-  $output .= '<div class="preview-image original-image" style="' . $original_attributes['style'] . '">';
-  $output .= '<a href="' . $original_url . '">' . theme('image', array('path' => $original_path, 'alt' => t('Sample original image'), 'title' => '', 'attributes' => $original_attributes)) . '</a>';
-  $output .= '<div class="height" style="height: ' . $original_height . 'px"><span>' . $original_image['height'] . 'px</span></div>';
-  $output .= '<div class="width" style="width: ' . $original_width . 'px"><span>' . $original_image['width'] . 'px</span></div>';
-  $output .= '</div>'; // End preview-image.
-  $output .= '</div>'; // End preview-image-wrapper.
-
-  // Build the preview of the image style.
-  $preview_url = file_create_url($preview_file) . '?cache_bypass=' . REQUEST_TIME;
-  $output .= '<div class="preview-image-wrapper">';
-  $output .= check_plain($style['name']) . ' (' . l(t('view actual size'), file_create_url($preview_file) . '?' . time()) . ')';
-  $output .= '<div class="preview-image modified-image" style="' . $preview_attributes['style'] . '">';
-  $output .= '<a href="' . file_create_url($preview_file) . '?' . time() . '">' . theme('image', array('path' => $preview_url, 'alt' => t('Sample modified image'), 'title' => '', 'attributes' => $preview_attributes)) . '</a>';
-  $output .= '<div class="height" style="height: ' . $preview_height . 'px"><span>' . $preview_image['height'] . 'px</span></div>';
-  $output .= '<div class="width" style="width: ' . $preview_width . 'px"><span>' . $preview_image['width'] . 'px</span></div>';
-  $output .= '</div>'; // End preview-image.
-  $output .= '</div>'; // End preview-image-wrapper.
-
-  $output .= '</div>'; // End image-style-preview.
 
-  return $output;
+  if (file_exists($preview_file) || image_style_create_derivative($style, $original_path, $preview_file)) {
+    $preview_image = image_get_info($preview_file);
+    if ($preview_image['width'] > $preview_image['height']) {
+      $preview_width = min($preview_image['width'], $sample_width);
+      $preview_height = round($preview_width / $preview_image['width'] * $preview_image['height']);
+    }
+    else {
+      $preview_height = min($preview_image['height'], $sample_height);
+      $preview_width = round($preview_height / $preview_image['height'] * $preview_image['width']);
+    }
+    $preview_attributes = array_intersect_key($preview_image, array('width' => '', 'height' => ''));
+    $preview_attributes['style'] = 'width: ' . $preview_width . 'px; height: ' . $preview_height . 'px;';
+
+    // In the previews, timestamps are added to prevent caching of images.
+    $output = '<div class="image-style-preview preview clearfix">';
+
+    // Build the preview of the original image.
+    $original_url = file_create_url($original_path);
+    $output .= '<div class="preview-image-wrapper">';
+    $output .= t('original') . ' (' . l(t('view actual size'), $original_url) . ')';
+    $output .= '<div class="preview-image original-image" style="' . $original_attributes['style'] . '">';
+    $output .= '<a href="' . $original_url . '">' . theme('image', array('path' => $original_path, 'alt' => t('Sample original image'), 'title' => '', 'attributes' => $original_attributes)) . '</a>';
+    $output .= '<div class="height" style="height: ' . $original_height . 'px"><span>' . $original_image['height'] . 'px</span></div>';
+    $output .= '<div class="width" style="width: ' . $original_width . 'px"><span>' . $original_image['width'] . 'px</span></div>';
+    $output .= '</div>'; // End preview-image.
+    $output .= '</div>'; // End preview-image-wrapper.
+
+    // Build the preview of the image style.
+    $preview_url = file_create_url($preview_file) . '?cache_bypass=' . REQUEST_TIME;
+    $output .= '<div class="preview-image-wrapper">';
+    $output .= check_plain($style['name']) . ' (' . l(t('view actual size'), file_create_url($preview_file) . '?' . time()) . ')';
+    $output .= '<div class="preview-image modified-image" style="' . $preview_attributes['style'] . '">';
+    $output .= '<a href="' . file_create_url($preview_file) . '?' . time() . '">' . theme('image', array('path' => $preview_url, 'alt' => t('Sample modified image'), 'title' => '', 'attributes' => $preview_attributes)) . '</a>';
+    $output .= '<div class="height" style="height: ' . $preview_height . 'px"><span>' . $preview_image['height'] . 'px</span></div>';
+    $output .= '<div class="width" style="width: ' . $preview_width . 'px"><span>' . $preview_image['width'] . 'px</span></div>';
+    $output .= '</div>'; // End preview-image.
+    $output .= '</div>'; // End preview-image-wrapper.
+
+    $output .= '</div>'; // End image-style-preview.
+
+    return $output;
+  }
 }
 
 /**