OS X :: Web Pages Takes Multiple Tries Before Loading Completely

I've got four computers (2 OSX, 2 XP)and an NAS networked and sharing internet via DSL from Verizon using their Actiontec GT704WG modem. All computers are connected via gigabit ethernet (NOT wireless, though the Actiontec wireless is used by some appliances in the house (Wii, iPhones, TiVo, Airport Express, occasional laptop). I am not using the router features of the Actiontec. I have 1 ethernet cable going from the Actiontec into a gigabit switch and the computers are connected to the switch. I can tell from the switch they are all networked at gigabit speeds (except for the Actiontec, of course).

File transfers and connections between my computers appears to be fine, but internet connections appear to get bogged down regularly. On all the computers, the biggest symptom I see is that pages will refuse to load or only load partially. Most of the time, if I reload the page, it will finally load, but sometimes it takes multiple tries before the page finally loads completely. The only way to fix the problem is to reset our internet connection. Sometimes just powering down the Actiontec for 15 seconds works. Most of the time, I have to power it down, and unplug it for 30 seconds. Sometimes I have to do this multiple times before everything is fixed and the computers can access internet again. I find I have to do this anywhere from twice a day to once every other day.