WOW !....
Yes, that template you are using on your forums is to image heavy and the images are not optimized at all.
Use this site to help you optimize your site:
http://gtmetrix.com/reports/www.allt...y.com/KwSpQi6p
It will give you a list of all the images you have to optimize and a link to the optimized version of each image so that you can just click, save and upload and replace them on your server.
You also have to add some type of caching to your files and add image dimensions to your images as well.
Fixing those 3 issues will greatly improve your site's performance and "probably" quiet hostgator down.
If you need help doing this let me know, I have some free time tonight.