I'm sorry to hear that your recordings aren't playing back very well. I can see you have an engineer booked to call round and get this fixed for you. It would be great to hear how you get on with the appointment afterwards so please keep me posted.
If it's only affecting recordings it is likely that the box may be replaced due to a hard drive error (If that's what the engineer’s findings are). If this is the case then I wanted to let you know in advance that you can copy over settings relating to Series Links, Wish Lists and Thumbs Ratings over to the new box should a new one be installed.
This will help save you a heap of time setting them all up again, you can find instructions on how to do this here: How to copy TiVo® settings
Sadly the recordings themselves will be lost, I am sorry for any inconvenience this may cause if it's the case your box is swapped out.
Please let me know how you get on, I'm here to help if you need me.
Tech fan? Have you read our Digital life blog yet? Check it out