I keep a spare for such tests. Made a little money from that.
I know there have been a few threads about the same situation, but mine varies a bit.
First off, I use Verizon DSL, and my modem is a Westell Model 2200. I don't use a router. I've called tech support, I've been through that whole process, and they claim it's a virus. So I used Defender Pro, which hasn't detected anything.
Personally, I believe it's my modem. It seems to be overheating. I've tried methods of cooling it and it SEEMS to work, but then it'll go out again. It doesn't seem to do it as often or as severely as when it's burning up hot.
Any ideas, suggestions, comments?