TBA in the EPG (TV guide) is a symptom that your box hasn't called home to get listings yet.
newapollo's suggestion should serve to refresh the channel list, I'm not 100% convinced it will load the data within the guide itself. It's easy enough to do - follow Home > Help & Settings > Settings > Network, and as long as the box's internet connection is working...
Either wait upto 6 hours for the auto-connection to run and populate the guide - check timing in the top-left
Manually select "Connect to Virgin Meda service now" at the bottom, and wait maybe 30-45minutes the first time round.
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