OK, I'm an idiot. I am using Oneiric 11.10, not Maverick 10.10. I was thinking that Oneiric was the name for the next LTS. So, I have a fresh install of Oneiric 11.10, now upgraded to the 3.2.1 upstream kernel, which has the same overheating issue as the standard 11.10. I had the same issue with 11.04.
OK, I'm an idiot. I am using Oneiric 11.10, not Maverick 10.10. I was thinking that Oneiric was the name for the next LTS. So, I have a fresh install of Oneiric 11.10, now upgraded to the 3.2.1 upstream kernel, which has the same overheating issue as the standard 11.10. I had the same issue with 11.04.