Some of our solutions capture original file names (e.g. img.yt) while others don't. That's because many image hosts do not include the original file name and you can't make a silk purse out of a sow's ear (as they say).
I know there are many image hosts out there that we could extract original image names from, because other rippers get some original image names we don't (e.g. Viper Ripper). So...
1.) If you are an IHG user and know another ripper gets the images and we don't, please report that in a topic, and we can upgrade our solutions to capture the file names.
2.) If you are an IHG solution developer, have a look at the HTML source of the page with the large image on it, and see if you can spot the image name (as separate from the file name). Often this will appear in an "alt=" or "title=" statement. If you see that, please work on your solution until you can supply the original name in your function's return to the IHG processing code.