Tried rescanning and they do not show up any one with any ideas.
Two separate computers one with the HVR-900 and one with the HVR-4000.
sbiddle: Where are you located? Are you using the correct transmitter site in the GB-PVR config application?
And lastly do you have anyway of testing your aerial such as a Freeview STB? There is a very high probabality the issue is your aerial or a signal related issue.