Loading Images On Many Websites?

I am having a strange problem loading certain websites from my new computer. I'm sure there is a relatively straight forward solution to my problem, but I am too ignorant to solve it myself. I have done plenty of google searching, but so far have not uncovered any solutions. My PC specs are in my profile.Very often when I search for an item on Ebay, or load a certain (legal) movie streaming website, the websites take a long time to load, and the thumbnail images do not load properly. i.e sometimes a few load, while the rest do not (e.g. just say "Item Image"). This problem occurs with both IE and Firefox. It is not the "Load Images Automatically" option in Firefox, as that has always been selected.

My computer has both a Wireless and LAN connection to my router. Usually only one of the connections is enabled. I have found a work-around that fixes the problem for a short while. If I try load the certain movie streaming website, and I am having problems, I disable the network connection (e.g LAN) and enable the other one (e.g. wireless). The website often loads then. If not, I re-enable it the way it was, and it usually works then. I can then access the site properly, although all the images still do not load - usually about 3/4 do. I am using a VPN to access the movie streaming site. However, I also access this site from two laptops in the house, both through the VPN, and they have no trouble at all loading the website correctly.