Ok looks like its computer specific then not really to do with the network equipment. What current web browser are you using? What I would do is try another web browser and see if the problem is still there with that browser. It could also be some type of spyware/malware..be sure you scan for said objects and viri.
Now days the term gateway/router are pretty much universal. This wasnt so back in the old people days, but now the term is used very loosely.