check w/your cable provider as well... I used RoadRunner in northern VA, they (of course) oversold subsriptions, and the network suffered. Packet loss was up around 5-6% during peak hours... I got about 5-10k a sec downloads.

you should run a tracert to yahoo.com or some other external site, and check the latency @ each hop. If the hop is internal to your cable providers network, then that is your problem.

keep your virus software up to date, don't run any executable attachments, and don't run any servers on your machine, you should be in pretty good shape.

-goose