Is it just your internet or cable tv also (digital mostly?) I had problems a couple of years ago where Comcast decided to lower the signal level to my neighborhood. Everything worked fine until then. Once they lowered the signal level I started experiencing loss of digital tv (freezing, etc) AND my cable modem would stop getting a sync every once in a while. I had them come out and they tried to tell me the cabling in the house had to be replaced as it was "the wrong type". As they put it in I was not happy with this.
In the end, I purchased a Motorola BDA amp (the BDA-K4/RA/PS), the power inserter and some 75 Ohm terminators for the unused ports.) It gave me a 7dB increase in the signal and I've had no problems since. As I don't have a basement I had to mount the unit on the outside of the house and didn't have a power outlet handy. I used the power inserter to send the power to the unit from an outlet inside the house. All parts, including a security screw for attaching the unit to the house, ran me less than $100.
In the end, I purchased a Motorola BDA amp (the BDA-K4/RA/PS), the power inserter and some 75 Ohm terminators for the unused ports.) It gave me a 7dB increase in the signal and I've had no problems since. As I don't have a basement I had to mount the unit on the outside of the house and didn't have a power outlet handy. I used the power inserter to send the power to the unit from an outlet inside the house. All parts, including a security screw for attaching the unit to the house, ran me less than $100.