Tivo gets stuck, freezes and powers up reapeatedly

Question

The Cable company sent out two service men to bring in a new box with HD for my TV and installed it. Since then the Tivo seems to freeze for a few seconds while watching something i taped and then it just got worse, as it starts to play it will freeze and got to black and power up again. So any show i start watching on my Tivo will not last too long before it freezes and repowers. Can you help?