Thanks, Ed, Steve, Alan and David :-)
I have tried krec, but got nowhere, at least partly because I didn't 
understand it.  Or is there another and different application called Krecord?
However, I must clearly try the Gnome program, and I want to try Jaunty, and I 
assume that the Gnome recorder will be available in Jaunty.  So I am trying 2 
things at once, have downloaded and burnt the Jaunty AMD64 iso and am about 
to install it on a spare partition on my recently acquired testbed machine.
I'll keep my fingers crossed.  If Doze recorder can only keep going for a few 
minutes, it wouldn't be much use anyway.
Lisi