I had a 9.10 to 10.04 upgrade that broke nothing.
It didn't even do stupid things with the DVB firmware, which previous upgrades have screwed up. Well, misplaced.
Of course there's a caveat. I haven't tried the HID event layer for the IR remote yet. :-) Previous upgrades have invariably moved that around.
Wade.
Q:Is it proper to eat cheeseburgers with your fingers?
A:No, the fingers should be eaten separately.