Losing Connection to the Internet

I keep getting the error that my cable boxes are unable to connect to the internet, and then they lock up.  I have to power them off and back on to recover.  This only started after comcast changed out my cable boxes and gave me the "improved" x1 boxes, which is cery upsetting  Does anybody else have this problem?  It happens 2 or 3 times a night and I can't watch any on-demand because of it.