I've just bought the full version of Blood, having already got The Way of All Flesh from, well, I'm not sure. Anyway, I'm now trying to play Even Death Can Die, but all the keyboard controls are different to what I'm used to. I'm gradually working out how to reset them but the big problem I have is with jumping. Caleb seems to have developed a tendency to only jump to the left, which is a bit unhelpful. I can't see any way to change it - any ideas. please?

That seems strange... First things first, are you playing B:FS or OUWB? I'm assuming B:FS.

Fresh Supply.

That sounds like it might be a keybinding issue.
Try going into:
%AppData%\Nightdive Studios\Blood EX
and then rename your kexengine.cfg file to something like kexengine.old, then see if it rebuilds it correctly when your run it the next time.

Checking the stdout.txt file in my game directory, it looks like it might want to have a user01 folder under Blood EX, with the kexengine.cfg file in there.