It sounds like your TIVO is losing the inbuilt internet connection.
Using your remote go to Home > Help & Settings > Settings > Network connection.
When was the last successful connection?
If you follow "connect to Virgin Media service" and wait around 30minutes then recheck, what does it say? (hopefully it will have reconnected and the EPG and on demand/catch up will be working again)
Dave
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali