I see that if I need to Resend all recordings it advises me Topfield PVRs will require a factory reset before resending any recordings.
Is this really necessary what are othere topfield 2460 users doing.
Another question how often does the EPG guide get updated I notice that my guide on my 2460 is showing tonights Nikita is starting at 11:00 but the Interactive epg guide on the site is showing it starts at 10:50
It depends on why you are resending all recordings. Usually this is only needed because the Topfield has stopped fetching the scheduled recordings or has stopped loading them correctly. When this happens you do need to reset the Topfield to get it working again.
The good news is that Topfield are working on a firmware update to fix the problem which is caused by the Topfield not updating the guide when shows start times or durations change. Topfield are also adding a clear guide cache menu option which will avoid needing to reset if something does cause the guide cache to become corrupted.
The guide gets updated every day sometime after 1pm (this could be at 2pm or even 4pm). The difference you saw between your 2460's guide and the Interactive guide is caused by the above mentioned Topfield bug preventing the 2460 from updating the guide.
This issue is address in the 22 November firmware for the 2400/2460. It is still to be fixed on the 7100+.
Update: updated firmware now available for 7100+.
All 3 firmwares have a propensity to stall downloads of timers and EPG data. Also reports of some timers not downloading and very occasionally timers inexplicably being deleted.
Risk minimisation strategy -- put the Toppy into standby for a short period each day.