Hi All, Thanks for your help. I'll try to sum up my response to several of your suggeations.
I'm using the ftp.debian.org mirror (the same as I have used for years on my X86 box) and apt keeps reporting that there is an error connecting - no such URL (or words to that effect -- it is the standard message when you put a bogus line in the source.list file). I never changed the security lines because I know that there is no unstable security :) I must have mis-read a news item a little while back that said X 4.2 was available in unstable :( Thanks, John