Thanks - but the height and width are not empty in the code. See my code below:
<?php
if(TRUE){ // Begin Cached Resized Image: ImageCacheInstance_1287416098580
ob_start();
?>
<img src="<?php echo $row_rsimages['full_size_url']; ?>" alt="" class="image0" height="250" width="200" />
<?php
echo(getCachedResizedImageHTML(ob_get_clean(), "image_cache", "fit", "#FFFFFF", false));
} // End Cached Resized Image: ImageCacheInstance_1287416098580
?>
For some reason it is only empty when the page loads.