I've recently had high speed internet installed. The installers used my DTV line and put diplexors outside and inside to split the signal. It runs into the attic and splits again to the multiswitch and then again out of the multiswitch to the line in the family room with the internet/DTV. Now my DTV that is on the same line with the internet is freezing up. The other DTV line in the bedroom is running fine(this line was only split once). These are HD receivers.
Do I need to upgrade the diplexors to Hi-Freq digital splitters?

There is no way to boost the signal or use different splitters? I guess I'm looking for alternatives to running another line.....

with the swm ... you might be able to use special diplexers for cable ...

but usually for the internet ....i wouldnt do it ...