I think this maybe an XP thing (although MCE should have been using same drivers). Many people seem to report no issues with the 7010ix under Vista / Win7 but I had massive issues with standby (but there again standby is heavily influenced by motherboard hardware, chipset drivers etc so was this working on different OS with same hardware?).I dont think they any thing wrong with my card.. today mediaportal but not let me add a program to record later on every time I tryed to add it mediaportal locked up. I have used the card with vista media center and MCE2005 and every thing worked well.
Does this card have two aerial inputs? If so are both of them plugged in? What it could be is that when watching live TV you are using tuner 1 which is working but when recording it will use tuner 2 which might not be. You should be able to test this reasonably easily as if you can start live TV and it is working you can then try and record a program from a different mux (ie. have BBC One on live TV and ITV on record). If both work then it will be standby related, if not then it is hardware / driver related.
A thought that is MCE/VMC just allocate cards in order regardless of whether you are watching live TV or recording then this would be different to how MP handles card allocation and might explain a few things?
Adding schedules does not use the card so that should not be related. That just reads/writes some info from/to the TV database. Without logs we will not be sure what is going on ...
A couple of things to try why I think about it....
disable the analogue tuners if you are not using them
try disabling DVB EPG
do you use mini-display plugin?
try closing the client (MP application) when have stopped using it. I have never found out the root cause but leaving MP open has sometimes caused me a few issues on resume. Closing MP before going to sleep seems to solve all of these.
try swapping the order of the cards round in TV config (ie. push the bottom DVB-T tuner to the top; this will switch around which card is preferred for live TV and recording)