Originally posted by: DarkKnight
could a signal booster improve the performance of cable internet?
Yes, but the effect won't be as dramatic as with the cable tv signals. As for a signal booster, you really need to be careful with what you get, as poor quality signal boosters will actually introduce more noise than amplifying the signal. Motorola makes a dedicated drop amp marketed as a "cable modem signal booster". B&M's like BB sell it for ~$80, but you can find it on ebay and some e-tailers for ~$40. I also saw one at my local BB for $45 as an open box item.
I installed one about 2 months ago and am also using an AsusTV 880. I'm guessing the lines are a result of a weak signal coupled with the CX2880's adaptive comb filter that is producing the wavy lines. Check to see how many times your signal has been split leading to the cable line where your tuner is. You may want to get some better splitters or run a single-split line to your TV tuner.
I replaced a splitter and bought the drop amp and my IQ is much improved; picture quality is excellent.
Chiz