Guide Plus have issued the following information on their website...
For Users in the UK.
Important Analogue Terrestrial Broadcast Information.
In the UK the Analogue to Digital switchover is well underway and due to be completed in 2012. However ITV1 GUIDE Plus+ services comes to an end on the 31st December 2010.
Therefore as from the 1st January 2011 GUIDE Plus+ services will no longer be available on remaining ITV1 Analogue Terrestrial services.
If you are using ITV1 as the Analogue Terrestrial Host channel you will need to change Host channel if possible. Analogue GUIDE Plus+ units have the possibility of using British Eurosport as the Host channel if also using a Sky Satellite receiver. GUIDE Plus+ units fitted with a digital terrestrial receiver may use BID TV as a host channel but some earlier models will not be compatible meaning that in this case you will no longer be able to use GUIDE Plus+ but may use the Freeview EPG instead.
Here is a list of models that have a Digital Receiver but are NOT GUIDE Plus+ compatible. If you have one of these devices you should use the Freeview EPG that is available.
Philips DVDR 7250H
Philips DVDR 7260H
Philips DVDR 5520H/05
Philips DVDR 5570H/05
Pioneer DVR 440HX
Pioneer DVR 540HX
Pioneer DVR 545HX
Pioneer DVR 940HX
Pioneer DVR 550HX/WV
Pioneer DVR LX60D/WV
Pioneer DVR LX70D/WV
Pioneer DVR LX01 (SDVR-LX70D/WV)
Pioneer DVR 560HX/WV
In other words... if you own one of the above boxes the Guide plus epg will no longer work and you will not be able to record programs in advance without setting the timer manually.
my advice, if you own an affected box is to contact the manufacturer and ask them to replace it F.O.C. or contact trading standards for help.
Darcy aka Inferno