Is this PC running on your local network or is this on some server somewhere?
On the PC, take a look and see if you can find out what the URL is of the images that don't show. I assume you get a place-holder icon of some sort? Maybe look at the "source" code on the PC and maybe that will help.
This is most likely some kind of addressing problem and you will have to change something in the cart on how it generates the URL for the images.
I'm sure it is looking in some folder that does not exist or is not being referenced correctly. Are you using absolute addressing or virtual (I think that's what they call it when you don't use a full url in the html ...
http://xxxx.com/some-image.jpgAl