ACPI Thermal Zones on HP dv5z (1008ca)

Lately I have been getting a hard lockup on a work laptop, and I suspect it may be temperature related. Unfortunately with the latest Karmic kernel (2.6.31-17-generic x86_64) I am seeing the following message on boot:

[ 0.943491] ACPI Exception: AE_OK, No or invalid critical threshold 20090521 thermal-384

Additionally, there is no output [...]