Cable Drop Out or No Signal
Normal oxidation in the air can mess up your high speed internet connections.
Disconnect and reconnect your cable lines from the splitter where it enters your house (inside). More than likely this will remove the oxidation and both your TV signal and High Speed Internet may improve. Do this every 6 months or so.
If you are interested in more information about High Speed Internet topics, Scot Finnie's site is an excellent resource, plus he has a newsletter you can subscribe to for free.
Tweaking, Testing, and checking the speed of your High Speed Internet connection.