Skipping issues: my experience and suggestions
I've had a couple rounds of "picture skipping" issues and thought I'd share my hard gained experience with the forum. Of course, YMMV...
The most common issue for me seems to be related to the coax connections. The boxes I have that are connected directly over ethernet have been pretty solid to the point where I ran a long ethernet for one box to get away from some of the coax issues.
The coax fed boxes are ASTOUNDINGLY sensitive to cable issues. The coax you have pretty much must be new, clean & decent cable. It must also be TIGHTLY connected. I had a RG6 run that was fine for regular satellite service that eventually needed to be completely replaced as it was just not cutting it. I've also had 2 instances where I moved the box or the modem around and the coax lossened just a tiny bit (less than a quarrter turn from SUPER finger tight) and both times this caused skipping as well.
Suggest going ethernet if you can or having any coax you have in place already replaced when they install.
The final skipping issue I had was modem related, I had too many config options set on the modem itself. (static IPs, DYNDNS, Port forwards etc etc) and this seemed to cause issues that were not resolved until a "factroy default" reset. Keep your modem config simple is my experience.