I think that "someone else on the net" might be me. If so, two points:
I'm running 64-bit Lucid (10.04) not 9.10; and when you contacted me
off list about this I did suggest that it would be worth taking it
back on, because I don't claim to be any sort of expert and others
might well have a better notion of how to do it!

That said, the only 64-bit Flash for Linux I could find was in
labs.adobe.com, and it does seem to work perfectly well for what I
want it to do (mainly: Youtube and the BBC iPlayer via Firefox).