I get occasional bad recording pixellation, so bad sometimes that it is unwatchable. I have also had recording that have chunks missing, up to 15 minutes went from a 1hour programme. I have spoken with support on 150, and they did the usual tests from their end, and I have done all the tests from my end. Now they are saying to wait 2 days to see if the problem clears, if it hasnt then call them back. It is obviously a dodgy hard drive. Why do I have to wait for it to mess up another recording???? I pay a lot for a service, and now have to wait before I can book an engineer to change my box...why. Perhaps its time I looked at getting a satellite dish.
There is no pixellation at the moment but I have only just deleted the bad recordings. When that bit of disk comes round again I will have the same problem again.... it is not the first time this has happened, but this time was the worst and affected the most recordings. Next time will be worst still, and I will then be looking at closing my account with virgin unless my box is changed!!!
It's not guaranteed to work, but you could try forcing the issue...
Go into your deleted recordings and permanently remove the offending recording. TiVo's disk management is a dark art known only to itself, but if the space taken by that recording is flagged as available immediately, it may just get reused a bit sooner.