Hardware Setup:
ActionTek GT-701 DSL modem (with wireless capability enabled) connected to a Netgear 8-port switch.
Four computers connected to the switch, plus one XBox.

Problem:
For the most part, my DSL line works just fine. On occasion, though, my network connection seems to just flatline. For example, my brother's online gaming hangs (the connection, not the game) for about 15-30 seconds. While running GrabIt (a newsgroup downloading program), I can see the graph drop from a decent download speed to zilch. Additionally, I can see more frequent intermittent drops of one or two seconds. BTW, I schedule my downloads so as to not interfere with his online gaming.

During the periods in which I have no connection to the web (online gaming, IE, FireFox, bittorrent, etc), I checked the DSL modem lights and the Netgear switch. Everything looks good on their end...

Despite the network connection drops, my ISP tells me that the modem has not been disconnected from their system in quite a while. Their records of when the connection dropped and/or reconnected match my records of when I made setting changes and/or manual power cycles.

So... A plea for help:
1) Anyone have any idea what the frell/smeg/frack is going on?
2) In an attempt to get more data, I would like to get a timed graph of when my connection decides to just drop. Definitely one with more granularity than one check per minute (I've found a few applications online but they usually do a check just once per minute). Checking each second would be preferable.... Anyone know of an application I can use? I considered just using the ping command but it doesn't give me time marks for each ping.