[eluser]pickupman[/eluser]
Wouldn't this be from calling the original images? The library works one file at a time, so you can't pass an array of file names to the library. You have $data['images'] above the thumbs. You need to call the array of images that contain your_filename_thumb.jpg as your source instead. Use directory_map() function to get array of files. Loop through the array and use preg_match() to find your thumbnails, and save to a "thumbnail" array. Then loop the "thumbnail" array in your view.
The other options to create thumbnail method, and stream the resized images on the fly like phpThumb.