I'm not sure exactly what it was, but eventually pretty much all of the innards of the laptop got switched out (mmm warranty) and that made it better. I'd guess that there was something a bit marginal in the hardware, and some kernel change just pushed it over the edge. No idea what or how.
So please feel free to close this one. -- recent dapper kernels causing lockups on Dell Latitude D600 https://launchpad.net/bugs/53578 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
