That was always the problem with Adam's material - every iteration of HHG was different and each one undermined the others.
But don't let that put you off. I still enjoy the TV series immensely, but it doesn't really gell with the radio series or the books. There is still some good material in the 3rd, 4th & 5th books, though after the third book it's reduced somewhat (the only things I found really funny in
So Long.. were the Rob McKenna stuff, Arthur learning to fly and a few of the guide entries) but hey, it doesn't all have to be ball-tearingly funny and it's all part of the story.
I think, had his life not been cut short, that eventually he would have ended up doing at least one or two more radio specials, and probably another series for BBC TV. The movie would have gone ahead eventually, though only god knows if it would have been any good.
And in an attempt to steer the thread vaguely back on topic -
Not proof, but heres the dialogue from
Tomb of the Cybermen -
Victoria: You probably can't remember your family.
The Doctor: Oh yes, I can, when I want to, and that's the point really. I have to really want to - to bring them back in front of my eyes. The rest of the time they sleep in my mind, and I forget. And so will you.
If the woman was intended to be his mother, then it sort of doesn't quite gell with that.
The implication I got from the juxtopositioning of Donna in the camera's eye when the doctor was asked about the lady in white by Wilf was that it was probably Susan. I'd also wondered if it was Romana.
Who knows really, it was fairly unspecific. I wonder what RTD's true intention was, and whether Julie Gardner is speaking from authority on the commentary or just musing?