Anyone tried one of those Motorola Cable Modem Amplifier thingies?  My
signal is at -10, which is right at the limit, and my connection routinely
drops.  It was -13, but they gave me a better modem and it improved to -10.
I put caps on all of the open cable ports in the house, but it didn't seem
to make my signal any better.  

Unfortunately, the people who built the house must have used cable made out
of xmas lights or something, because the farther you get from where it comes
into the house, the worse the signal.  I ran new cable from the entry point
down to my cable modem, but I think the other crappy cable in the house is
causing problems.  I have splitters, but they all come after the main block,
which the cable modem is plugged into.  

Jay