Hi Alan,
This error has only appeared a few times on the 360.
It does appear to be a probable hard drive problem. What happens if you pause and rewind live TV as that is the same as recording?
How much free space is showing on your hard drive?
Recordings > Recorded > View all > It will show a percentage in the top left hand corner of this screen
One previous solution for a poster was, "The white converter lead mush be a bit dodgy. Upon wiggling the cable the 360 box picture broke up. I swapped the lead for a standard f type to standard ariel adapter and that solved that problem. "
I know you've already checked cabling, but double check that small connector and make sure it isn't slack (strengthen it temporarily with sellotape if necessary)
If that doesn't help then you should call 150 from a Virgin landline, or 0345 454 1111 from any other phone, option 2 (Faults)
Or wait a day or two and a member of the Forum Team should pick this up for you and arrange a tech visit.