Replacement DVR

I currently have the Motorola DCX3400-M DVR and it appears to be slowly deteriorating over time.  There are times when we watch OnDemand programming and the DVR locks up, the only way around this is for us to reboot the box.  

A few of our channels have broken audio on the HD channel but the same SD channel audio is fine.  

When changing channels using the remote, the DVR stops responding.  The display on the DVR reacts properly to us pushing buttons on the remote, but the channels will not change. When the box finally reacts, it will fly about 5 channels in either direction.

When watching recorded programming, we attempt to fast forward through commercials, but when the commercial is over, the program will not react properly to our button pushes.  The DVR display, again, reacts properly to our button pushes but will not play and ends up fast forwarding completely through what we have recorded or far enough that we need to rewind and hopefully not have the same problem again.

I know these are all minor problems, but I was just wondering if this is something that would rate a replacement cable box? Each of these problems are not a hard failure, but occur very randomly.