Going on eBay disrupts my internet connection

Every time I go on eBay, logged in or not, I click on a couple of pages, and then it goes into 'looking up eBay' mode, then says connection to server cannot be found. So I close out of my browser, try again, sometimes two or three times more, before it lets me navigate eBay. Once I'm in the site, I'm good until I leave and try to get back on again. Same frustration. When this happens, on the bottom right of my computer where it shows the signal strength of my internet connection, a yellow exclamation point shows, I place my cursor over it and it shows no connection for about twenty seconds. It's so annoying! My boyfriend has no problems getting on eBay with his computer, and it's the same one I have, but he does have random problems with the internet connection whereas mine are usually just with eBay. Could our Belkin be the problem? If we both lose connection, we unplug it and plug it in again and after a minute it works. Oh, I use Firefox as my browser, but I have used IE and the problem still occurs. Any thoughts?

Logged into the same site isn't the issue here, either. I'm on eBay far more than he is. I think it may be the wireless router too. A couple weeks ago we were about to buy a new one, but decided at the time we really didn't have the money for it. We have had it for five years, actually longer. I think it is time to replace it.