Is your live TV picture OK? That will ID if the problem is the incoming signal.
Now try pausing live TV and watching delayed by a short time - this is also a recording and uses your HDD in the same way. If this is also affected, your TiVo has a failing hard drive which will end with a tech visit to replace your box with a V6.
It's not something that can be repaired or will get better.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks