When you were using your old VCR, the signal from the aerial was feeding to one analogue tuner in the VCR (which fed its output to the tape) and also to another analogue tuner in the TV (which fed its output to the screen and speakers). So it was possible to tune in two stations at once, with different destinations for the signals.
If you're using your DVDR with an analogue TV set, you've only got one digital tuner available, so you can only tune in one channel at a time. You'll be able to watch an analogue channel on the TV (using its own analogue tuner) while recording a Freeview channel on the DVDR (with its built-in digital tuner) but you won't be able to watch one Freeview channel while recording another. To do so, you either need to upgrade your TV set to one that has a digital tuner built-in or, far cheaper, invest about �25 in a cheap Freeview box to feed a digital signal into your TV's Scart socket. (If your TV has only got one Scart socket you might also need to purchase a Scart switching box, so that you don't have to keep changing the leads feeding from the DVDR or Freeview box).
Chris